Unit 6: Law and Criminology

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Unit 6 Introduction

“Judge, my brain made me do it,” says the defendant in court. In some sense that is true, because all behavior is caused by brain function—but should the law give anyone a pass just because of this? That’s a complicated question, which calls for an understanding of both neuroscience and law. In this unit we will explore the many ways in which neuroscience intersects with the law. Among these are: the neuroscience of ethical and law-abiding behavior; why some people have a tendency to commit criminal offenses; the different reasons we have for punishing offenders and how those reasons relate to the brain; and the ways in which neuroscience might assist in the courtroom by clarifying the limits of eye witness identification, measuring “pain and suffering,” and even detecting lies.

What's In This Unit?

  • Lesson 1: The Hows and Whys of Punishment
  • Lesson 2: Risk Factors for High-Risk Behaviors
  • Lesson 3: Eyewitness Testimony
  • Lesson 4: Lie Detection
  • Lesson 5: Guilt & Responsibility
Terms & Definitions: Unit 6 
  • Polygraph – A machine used for lie detection, which measures three different signs of autonomic arousal: blood pressure, heart rate, and respiration rate. Because most people are nervous when lying, their autonomic “fight or flight” response is activated and these three measures increase.
  • Environmental Toxins – Chemicals or other factors that harm or adversely impact the development of the child (in the womb or throughout childhood) as well as adults. Can be found in the air or water and can include lead (in paint, automobile exhaust) chemical pesticides, chemicals found in cigarette smoke, etc.
  • Psychopathy – A set of behaviors and traits associated with crime and antisocial behavior, including being self-centered, charming, and manipulative but also lacking guilt and empathy for others.
  • Antisocial – Behavior that disregards the well-being of others, including directly harming others and doing so indirectly by breaking laws. This term comes from being “anti” society and the people in it, and does not mean someone dislikes socializing.
  • External Validity – Whether the results of an experiment can be applied beyond (or “external” to) that experiment. For example, an experiment on methods to boost learning in one high school probably has good external validity for high school students more generally, but its external validity for kindergarten students is more questionable.
  • Internal Validity – Whether the reasoning that links the experimental design, the data and the conclusions (all “internal” to the experiment) are valid or not. For example, consider an experimental program to decrease criminal behavior that uses self-reported criminal behavior as its data. If its conclusions claim to pertain to actual criminal behavior, then it has a problem of internal validity—just because people say they are committing fewer crimes, doesn’t mean they are.
  • Fear Conditioning – A kind of simple learning that all creatures, including humans, automatically do. When a cue stimulus, such as a tone, is always followed by a fear stimulus, such as an electric shock, we eventually learn to feel afraid of the cue stimulus.
  • Mentalizing – Process of attributing mental states to others, often automatic for most people. For example, we know how someone is feeling if we see them cry (sad) or what someone is trying to do if we see them repeatedly wiggling a key in a locked door (trying to open it).

Lesson 1: The Hows & Whys of Punishment 
Students will be able to explain some of the reasons why humans choose to punish wrong-doers and what that means for our justice system.

ENGAGE/HOOK: The Pros And Cons Of Neurolaw  (10 min)

Introduce the lesson by guiding students through the following activity:

  1. Have students watch this video (from Seeker by The Verge) to get them started thinking about how neuroscience can inform our systems of justice and punishment. [Caution: contains some coarse language]. 
  2. After the video ask students to discuss the questions below:
    • What are some pros of applying brain imaging and other neurotechnologies in the courtroom?
    • What are some cons of applying brain imaging and other neurotechnologies in the courtroom?

Optional: Review some of the neurotechnologies mentioned in the video and discuss what they do and how they work (see information about non-invasive technologies in Unit 3, Lesson 1). Ask:

  • What are some ways in which brain science might be used to inform our perception of a person’s responsibility for committing a crime?
  • What are some limitations of our current understanding of brain science?
EXPLORE: Rationales For Punishment  (20 min)

Guide students through the following activity in which they will match different statements to four forms of inflicting punishment. 


Begin by explaining the background on punishment and defining the forms of punishment:

The minds and brains of modern humans may have been shaped by evolution to favor punishment, but punishment is more than just a reflex reaction. We generally think about whether and how punishment should be imposed, and we have reasons for punishing that may be different in different circumstances. Here are some different rationales for inflicting punishment in our society:


If people know they will suffer an unpleasant punishment when they break society’s rules, they are more likely to obey those rules.



When someone has done something bad, then the rest of us may feel that person deserves to suffer in some way. Just as we feel someone who does something kind or heroic deserves our thanks or a reward, when someone does something cruel or unfair we feel they deserve punishment (“justice is served”).


To sequester someone is to keep them away from others. This rationale is intended to protect citizens from dangerous people by incarcerating them and therefore keeping them from hurting others in society.


This sentence is not meant as a punishment but as a way of improving the person and making them less antisocial. Drug treatment, education, psychotherapy and job skills training are sometimes offered or even required before the wrong-doer is allowed to rejoin society in a hopefully more productive way than before.


Read the statements in the left-hand column below aloud and have students try to match each quote about punishing wrong-doers to the four rationales for punishment (shown in the right-hand column). Have them justify their reasons.

     1 - deterrence
     2 - retribution
     3 - sequestration
     4 - rehabilitation


“By sentencing him to death, we can be sure he will never kill again.”

3 - sequestration


“Our loved one lost his life because of this criminal, so he deserves even worse than his 20-year sentence—he got off easy.”

2 - retribution


“Son, this whooping hurts me more than it hurts you.”


1 - deterrence

4 - rehabilitation

“You will be an old man by the time you get out of prison, so society will be safe from you.”

3 - sequestration


“In view of your good previous record, and the fact that your crimes were all committed under the influence of alcohol, I am sentencing you to intensive therapy for alcoholism.”

4 - rehabilitation


“She deserves to rot in prison for the rest of her days on earth.”


2 - retribution


“This will teach you not to lie to your father in the future.”


1 - deterrence

4 - rehabilitation

“If you are going to change the rules and start towing people’s cars when they park here, you better tell people about it first.”

1 - deterrence


“The judge sentenced me to anger management therapy.”

4 - rehabilitation

“I don’t deserve to pay a $500 fine for littering, because I only dropped one little Kleenex.”

2 - retribution


EXPLAIN: How Do We Make Punishment Decisions?

The following information is teacher-facing and can be utilized to teach students new information in whatever format works best for you and your students.

Key Points:

  • Humans have evolved to want to punish wrong-doers for a variety of reasons, some related to the concept of justice, some related to preventing future harmful actions and promoting social cooperation.
  • When deciding upon an appropriate punishment, areas of the brain involved with both emotions and cognition consider the harm caused by the crime as well as the intentions of the perpetrator.
  • Punishment through negative consequences can be used to change behavior in certain contexts but can also lead to harmful long-term impacts.

Punishment for bad behavior is ubiquitous, from a parent telling her teenager, “you’re grounded!” to a parking officer ticketing an illegally parked car. In the criminal justice system, punishments can be much more severe, as in a prison term or even the death penalty. 


Why do we punish?
Some scientists believe that humans evolved to want to punish wrongdoing. By punishing antisocial behavior like stealing or harming others, people made their communities safer and were more likely to survive, which meant they all passed on their genes to the next generation, including those “punishment instinct” genes. But studies have also shown that various cultures and communities enforce their rules for fairness and pro-social behavior differently. Some studies have shown that the larger the community (with more interactions among strangers), the more likely community members are to support punishing wrong-doers. In a large community, a wrong-doer is more able to commit their crime again and again in new parts of the community, so punishment is often favored to enforce and maintain social norms and rules. 


To look more closely at why people might want to punish a wrong-doer, neuroscience research has used fMRI to scan the brains of people making punishment decisions. This research shows that deciding to punish a wrong-doer creates neural activity in the brain’s reward center. Therefore, it feels good to many people to punish someone they believe has done something bad… which may not be the best rationale for punishing someone in our society!


Determining punishment
Our decisions about whether and how someone should be punished for a crime involve a combination of feelings and logical thought, shaped by individual experience. Neuroscientists have identified areas of the brain involved with both emotion and cognition that play important roles when people decide on what an appropriate punishment for a wrong-doer might be (see more information about brain anatomy in Unit 1, Lesson 5). Areas of the brain associated with emotion, such as the amygdala, are involved in reacting to how bad, cruel, or harmful the criminal action was. We use other brain regions to make assumptions about the intentions of others, a process known as mentalizing. When people consider if a harmful action was intentional, they use these parts of the brain. Finally, people must put information about harm and intentionality together to come up with a level of punishment to recommend. This integration (a type of executive function) is thought to be performed by the dorsolateral prefrontal cortex (shown below in blue) by bringing in information from many other parts of the brain. 

A side or lateral view of the human brain is seen with the top part of the frontal lobe colored blue.

The dorsolateral prefrontal cortex (shown in blue) is a region of the brain important for many types of executive function, planning, and cognition. Image credit: BioRender.com

Punishment and behavioral change
Can punishment lead to behavioral change? Psychologist B.F. Skinner developed the concept of operant conditioning, which suggests that behavior is shaped by the consequences that follow—individuals are more likely to repeat behaviors when the consequences reward or reinforce those behaviors, while avoiding behaviors that result in consequences of punishment.


Principles of operant conditioning are commonly used in parenting, education, and therapy, but changes in behavior depend on the individual, the context of the behavior, the timing and frequency of consequences, and other social factors. Punishment can also activate the threat response in the brain, leading to chronic stress, anxiety, and other harmful long-term impacts.


Animal studies are helpful, but aren’t always relevant to discussions of complex human behavior. Research looking into human responses to rewards and punishments are variable—while some people are more responsive to rewards than punishments, others are the opposite! In light of this, does it always make sense to punish wrong-doers?  


Additional Resources
ELABORATE: Operant Conditioning  (30 min)

Guide students through the following activity in which they will explore operant conditioning.

  1. Pose the following scenarios to your students and ask them to decide which scenario they find most motivational.

    Your room is messy and your parents want you to clean it. 
    Which of the following scenarios is most likely to motivate you to clean?


    If you clean your room by the time I come home from work, I’ll give you twenty dollars.


    If you clean your room by the time I come home from work, you won’t have to do the dishes after dinner.


    If you keep leaving your dirty clothes on the floor of your room, we are going to have a very long talk, and I guarantee it won’t be pleasant!


    If you keep leaving your dirty clothes on the floor of your room, I’ll take your phone for a week.​​​​

  2. Ask students to share with the person next to them which scenario they chose. 
  3. Poll the class to see which was the most popular scenario.
  4. Explain that the idea of operant conditioning involves four types of consequences. (Optional: video explanation of operant conditioning)
    • Positive reinforcement - something is added to encourage behavior
    • Negative reinforcement - something is removed to encourage behavior
    • Positive punishment - something is added to discourage behavior
    • Negative punishment - something is removed to discourage behavior
  5. Have the class identify which of the above scenarios corresponds to each type of consequence:
  6. Finally, have students individually reflect on and write answers to the following questions:
    • What do you think is more effective in getting someone to do what you want: giving them a reward, or giving them a punishment? Explain your reasoning.
    • How do you think offering BOTH a reward and a punishment would work in this scenario?
    • If you could use any method in the world, how would you approach the problem of getting a poorly behaved kid to start being polite and respectful?
    • Give an example of one of the four types of consequences above that you’ve either witnessed or personally experienced recently. 

Lesson 2: Risk Factors for High Risk Behaviors
Students will be able to identify biological and environmental factors that increase a person’s risk for criminal behavior, including ways in which the adolescent brain and behavior differs from that of an adult.

ENGAGE/HOOK: Teenagers And Risk  (10 min)

Guide students through the following game that simulates the Balloon Analog Risk Task or BART. Introduce the activity using the following background information:
In this game, students will pump up a balloon until it pops. They earn money when they cash out, but the bigger the balloon gets, the bigger the cash out is!  It’s hard to predict exactly when the balloon will pop as it pops at a slightly different point each time, which makes it fun and exciting to push the boundary and see how far you can pump up the balloon.

  1. Ask students to open this online risk-taking game simulation
  2. Ask students to record the amount of money they made after 10 balloons and then answer the following questions:
    • How much money could you earn over the course of 10 balloons?  
    • Who do you think tends to earn more money during this game: children, teenagers, or adults?  Why?
    • Who do you think tends to take more risks during this game, children, teenagers, or adults?  Why?
    • When was the last time you did something risky in front of your peers?  Why did you do it and how did you feel?
  3. Explain to students: 
    • During this game, adults tend to cash out with each balloon at a lower value, as they are less willing to risk the balloon popping. Teenagers especially engage in far greater risks on the BART and other games of risk or gambling, especially when peers or their friends are watching them!  People who take risks on games such as the BART are often more likely to make risky choices in their real lives, including risky driving behavior.
    • Additional information on teenage risk taking can be found in this video, Peer Influence and Adolescent Behavior (from PBS Brains on Trial), where Dr. Larry Steinberg demonstrates a task in which their lab studies brain activity in adolescents while making risky decisions in the presence of peers.
EXPLORE: Group Data And Individual Outcomes (20 min)

Guide students through the following discussion about group data and individual outcomes.

  1. Begin by guiding students through the following grounding scenario. 
    • On average men are taller than women. 
    • Select one female student as an example and ask the class, “If we randomly select the next male that walks by the class, will she be taller than him?” 
      • To get students thinking you could switch a tall female student for a short female student and ask the question again. 
    • Ask students: What factors affected the uncertainty of our predictions about height?
  2. Now split the class into three large groups and assign each group one of the scenarios below to consider further. 
  3. Ask groups to answer the following question, using their scenario as evidence. After groups work through their scenarios, ask them to share their insights:
    Can we make predictions about an individual person’s behavior or biology based on the average data collected from a group? ​​​​

    Group 1:

    You have a headache. Decades of evidence, based on clinical trials with thousands of people, show that aspirin is effective in treating headache symptoms. So you take aspirin, but your headache persists. Why didn’t it work for you?

    Group 2:

    In baseball, left-handed hitters have a higher batting average than right-handed hitters because most pitchers are right-handed. (The motion of the ball thrown by a right-handed pitcher lines up better with the stance of a left-handed hitter.) Your favorite hitter is left-handed, but today he struck out at every at-bat! Why didn’t he perform better than right-handed hitters today?

    Group 3:

    High school students who sleep 8 to 10 hours every night statistically perform better on tests. Last night you slept for 9 hours but you failed your math test this morning! Why didn’t your long night of sleep help you pass your test?

  4. ​Finally, guide students in connecting their insights about data interpretation to scenarios in the real world: 
    • Laws are written with groups in mind and then applied to individuals. The challenge of using group data to draw conclusions about individuals is a particularly tricky conflict between neuroscience and law. Scientists, on one hand, look for group patterns to come to a general understanding of the world. Courts, on the other hand, are looking for evidence specific to the case—or defendant—at hand. 
    • Consider this example: Through studies of men displaying severely violent behavior, scientists have discovered that they all carried a variant of a gene called MAOA that blocked production of a particular enzyme. In mice, lowering levels of this enzyme also causes increased social aggression. Let’s think about how these findings might be used in the justice system.
  5. Ask students to silently and independently consider the questions below about the final scenario:
  • Do you think there is sufficient evidence to say that the MAOA variant is a biological risk factor contributing to an individual’s violent behavior?
  • What other experiments (in either humans or animals) would you conduct to understand the association between MAOA variant and violent behavior?
    • Potential experiments might include genetic testing a larger sample size of men with a record of violence or testing a large and diverse sample of nonviolent men to look for the strength of the association between the variant and violent behavior.
    • Students may also bring up privacy laws that may be in place, limiting genetic testing without permission (unless prisoners were tested previously before incarceration, via 23andMe or others)
  • In scientific results, the strength of an association is often expressed in probability, percentage, or likelihood (“there’s a 60 percent chance it will be raining at 3 pm tomorrow”). How strong of an association between MAOA and violent behavior do you think should be required for it to be considered as a risk factor?
  • Overall, how do you think scientific data about risk factors in a population should be applied to draw conclusions about a particular individual? 
EXPLAIN: Biological And Environmental Risk Factors

The following information is teacher-facing and can be utilized to teach students new information in whatever format works best for you and your students.

Key points:

  • Normal patterns of brain development in adolescence lead to increased likelihood of high-risk behavior.
  • Childhood exposure to environmental stressors, along with biological factors associated with fearlessness, are correlated with the likelihood of future antisocial behavior, although scientists cannot say for sure if they directly cause such behavior.
  • These factors cannot predict with certainty whether a specific individual will commit a crime in the future.

Adolescent brains and impulsivity
Simply being a teenager increases the likelihood of high-risk, and potentially antisocial, behaviors. By adolescence, the brain’s reward system (the “go!” signal) has fully developed, seeking new experiences and sensations as teens explore their limits and independence. Risky behavior can be a way to express emotion, seek thrills to enhance positive emotions, or engage in self-destructive behavior as a result of negative emotions. Peer pressure and the desire for social acceptance can be an extra push, as social rewards are especially compelling to teens. This is why avenues for interacting with their peers (such as messaging on phones or computers) are so compelling to teens, often making it difficult for them to turn off messaging devices to focus on their schoolwork or jobs. 


While all these reward signals are being processed, the teenage prefrontal cortex (the “stop!” system) is not yet mature, still working on weighing consequences, controlling impulses, and making decisions. However, environmental factors like family support, socioeconomic status, social norms, and access to role models and resources can change how different individuals navigate high-risk circumstances. For more on the developing teenage brain, see Unit 2.


Other biological and environmental predictors
In the film Minority Report, based on the book by Philip K. Dick, people are arrested for “pre-crime” on the basis of the psychic predictions of future crime. Could a program like this, relying on predictions based in biology rather than psychic forecasts, ever become a reality? Studies in which groups of individuals are followed from birth to adulthood suggest a set of factors that may increase the probability that an individual will grow up to commit violent crimes. These include prenatal exposure to toxins such as alcohol, tobacco, and lead, and social stressors such as experiencing maternal rejection during infancy. Measurements of heart rate during childhood are also associated with later aggression. Studies of thousands of children have repeatedly demonstrated a strong link between having a low resting heart rate (which may indicate fearlessness and stimulation-seeking) and antisocial/violent behavior. Atypical fear conditioning at age 3 also predicts crime at age 23, meaning that those children who showed less fear at a young age were more likely to commit a crime later in life. As with many predictors, this likely represents a combination of genetic and environmental factors (refer to the Launch Lesson for more on genetics and environment).

Interpretations and ethical considerations
It’s important to remember that brain differences are not evidence of fate or an unchangeable condition. Interpreting behavioral results (such as poor fear conditioning) can only be applied at the group level and are far from being specific enough to be used to predict an individual’s behavior. In addition, crime results from complex interactions of biological and environmental factors; it cannot be explained solely by neurological or behavioral traits. However, researchers are studying potential interventions to decrease the likelihood of future antisocial behavior, including nutritional supplementation, parenting classes and home visits from nurses, enriched preschool programs, and coping skills programs for teenagers. Should this research prove useful at identifying these children, these efforts should be used to benefit those children who are at greatest risk and to design interventions that are tailored to their needs.


Additional Resources
ELABORATE: Teenage Risk-taking And Social Policy (30 min)

Guide students through this New York Times activity about the age of responsibility. They will discuss what standards society should use to determine when a person is old or mature enough to be treated as an adult.

  1. Ask students to first share out responses to the following questions:
    • Think of a time when you were told that you were not old enough to do something. How did you feel? 
    • Did you feel you had any power, control or say in that decision? Did you agree or disagree with the decision and the reasoning behind it? Why?
  2. Next, have students complete the Act Your Age worksheet from the NY Times. Direct them to fill out the first blank column to the best of their ability. 
  3. When they are finished, reveal the correct answers to the Act Your Age worksheet, and then give them a few more minutes to jot down their ideas about whether these seem to be the appropriate ages.
  4. Reflect on student responses by asking: 
    • Did most students know the correct ages? 
    • Did any of the legal ages surprise them? If so, which ones, and why? 
    • Did multiple students seem to feel that any of the legal ages was particularly unfair? Which ones, and why?
  5. If there is time, have students read the article “How Old is Old Enough?

Lesson 3: Eyewitness Testimony
Objective: Students will be able to identify aspects of attention and memory that may impact the accuracy of eyewitness testimony.

ENGAGE/HOOK: Inattentional Blindness  (10 min)

Introduce this lesson by guiding students through the following video analysis:

  1. Show students this Brain Games video on inattentional blindness (a method used by magicians to deceive audiences).
  2. After the video ask students to answer the questions below:
    • As you watched the first time, what other changes besides the food did you notice?
    • What changes did you miss?
    • How do you think this phenomenon could affect eyewitness testimony? 

Note that some individuals will be able to notice the change, while many initially do not.

EXPLORE: Mistaken Memory  (15 min)

Guide students in the following activity in which you try to implant a memory (adapted from Neuroscience for Kids).

This activity demonstrates how humans tend to fill in the gaps in their memory with content that is similar to what they do remember and with what makes sense. 


Round 1: 

  1. Read the following list of words to students:
    • List 1A: read, pages, letters, school, study, reading, stories, sheets, cover, pen, pencil, magazine, paper, words
  2. Wait 5 minutes and then ask them which of the words in the following  list (list 1B) they remember also being in List A:
    • List 1B: house, pencil, apple, shoe, book, flag, rock, train, ocean, hill, music, water, glass, school
  3. Analyze: 
    • Which words did students falsely remember being in List 1A? Did they say that "book" was on list A? Only pencil and school were on list A.

Round 2:

  1. Read the following list of words to students:
    • List 2A: sheets, pillow, mattress, blanket, comfortable, room, dream, lay, chair, rest, tired, night, dark, time
  2. Wait 5 minutes and then ask them which of the words in the following  list (list 2B) they remember also being in List A:
    • List 2B: door, tree, eye, song, pillow, juice, orange, radio, rain, car, sleep, cat, dream, eat
  3. Analyze: 
    • Which words did students falsely remember being in List 2A? Did they say that "sleep" was on list A? Only pillow and dream were on list A.

After both rounds guide student through the following reflection:

  1. Ask students: Why do you think you might have made mistakes in remembering which words were on the first list in each round?
  2. Show the video “Can You Trust Your Memory” (from Seeker by The Verge) to give an overview of several studies into false memories and how prevalent they really are.
EXPLAIN: Attention, Memory, and Eyewitness Testimony

The following information is teacher-facing and can be utilized to teach students new information in whatever format works best for you and your students.


Key Points:

  • The brain uses both unconscious “bottom-up” and conscious “top-down” attentional networks to filter information about the world.
  • Memories are subject to alteration or manipulation every time they are recalled.
  • Other factors, such as emotional state or environmental cues, can influence what someone remembers or how well they remember certain details, which can become a major factor in eyewitness testimony or someone testifying in their own defense.

Attentional Filters
There’s a lot going on in the world around you. Your brain plays a crucial role in filtering out irrelevant information. What we think of as paying attention involves coordinating different neural networks that work together to direct and maintain focus. “Bottom-up” attention is driven by sensory stimuli that stand out in the environment that you can’t help but notice—think about things like bright colors, faces, or motion. “Top-down” attention is what you consciously focus on, based on prior knowledge, planning, and motivation. These filters affect what information is selected for attention. Your brain might emphasize or prioritize certain details over others, influenced by your expectations, emotional state, fast-paced events, or an unfamiliar environment.


False Memories
As discussed in Unit 2, Lesson 2, memory requires not just encoding and storing pure facts but also context. As such, memories are susceptible to distortion or manipulation. For example, leading questions or suggestive language can alter a person’s recollection of an event. People may feel compelled to conform to the expectations of authority figures to the degree that they incorporate false information into their memories. Exposure to a mix of different sources can result in confusion about what they experienced firsthand. And every time a memory is recalled, it can be subject to change. All of these factors make memories less solid and less reliable than many people believe.


Experts have advocated that educating police, jurors, and judges about how memory works, and the fallibility of memory, can help them evaluate eyewitness testimony more critically. New technology, like DNA testing from materials found at crime scenes, can help exonerate falsely accused people. The Innocence Project, which uses these kinds of scientific advancements to overturn wrongful convictions, estimates that 68% of their cases of wrongful convictions involved a mistaken identification of the accused person via eyewitness testimony. The Association for Psychological Science is also committed to educating the public and exploring factors that contribute to false eyewitness accounts and false memories that lead to wrongful convictions.

Additional Resources
ELABORATE: Be an Eyewitness (30 min)

Guide students through an eye witness activity adapted from a teaching tool produced by the American Bar Association

Many people don’t realize how unreliable eyewitness accounts can be and how difficult it can be to remember details after the fact. This activity will help demonstrate these issues. 

  1. Break students into pairs and hand out the image of the 1770 Boston Massacre, turned upside down to hide the picture. One student will act as a witness to a crime and one will act as a Police Officer investigating the crime.
  2. Signal the witnesses to turn over the paper and study the picture for 15 seconds. Then turn the picture face down again. 
  3. The second partner acting as a police officer will now question the witness about what they saw and record notes to report to the class.
  4. When interviews with witnesses are done, ask one of the police interviewers to give their report. Record observations on board and do not ask clarifying questions as it may suggest information. 
  5. Ask another police interviewer from a different group to share what their witness saw. Circle on the board facts that had been shared earlier and write in a separate space any additional facts or facts that contradict earlier reports. 
  6. Repeat #5 for all police reports. Witnesses do not talk. 
  7. Ask the class to discuss:
    • What was observed by our eyewitnesses?  
    • Do we know what happened?  When?  Where?  Who?  
    • Do we have a description that helps us accurately identify any suspect?  
    • Are witness memories the same?  
    • How is it that witnesses remember things differently?  Will the eyewitness testimony in court be convincing to a jury? 

Lesson 4: Lie Detection
Students will be able to describe how a polygraph works, its reliability, and how this technology is similar and different from fMRI lie detection.

ENGAGE/HOOK: Polygraphs   (10 min)

Introduce polygraphs and gather student background knowledge as follows:

  1. Show students this humorous video clip about the polygraph from The Simpsons (30 sec).
  2. Show a segment of this PBS documentary (beginning of the episode to 2:54) about the history of the lie detector. Note that the remainder of the ten-minute video recounts the fascinating yet complicated history of the development of the polygraph, but includes some images of and references to violence and abuse.
  3. Lead a discussion with students by asking: 
    • Have you seen lie detectors in the media?
    • What do you know about how polygraphs work?
    • Why might people perceive machines to be more accurate than humans?
EXPLORE: The Speed Lying Task   (30 min)

Guide students through a speed lying task. Can you spot when someone is lying?  Are certain types of lies easier to spot?  Let’s find out in this activity!

  1. Give each student a copy of the “Lie Detection Questions” worksheet.
  2. As a class, decide on six lie detection test questions and record them on the lines provided. Some examples provided below.
    • Possible lie detection questions to use (other examples with lying instructions):
      • Have you ever broken a bone?
      • Do you have any food allergies?
      • What’s the last movie you saw that you hated?
      • Where were you born?
      • Do you have a pet?
      • Have you ever cheated on a test?
  3. Break students into pairs. 
  4. One partner is the “detective,” and asks all 9 questions, including the baseline questions to the “liar.”
  5. The other partner is the “liar.” Without telling the detective, the liar gives false answers to any three of the test questions.
  6. After asking all of the questions, the detective then attempts to guess which three answers were lies.
  7. After completing the activity, show students this “How Do Polygraphs Work” video (3 min). 
  8. Ask students to discuss:
    • Why do you think some of these physiological responses could be related to lying?
    • Some of the questions the detective asked were yes/no questions, while others were open ended (where were you born). How do you think this might impact the experience of lying and how difficult it is to detect the lie?
EXPLAIN: Lie Detection

The following information is teacher-facing and can be utilized to teach students new information in whatever format works best for you and your students.

Key Points:

  • Polygraphs essentially measure anxiety and stress, and can ultimately not reliably distinguish between this broad response and a lie.
  • Our current interpretations of brain activity through fMRI are no better at detecting lies than a polygraph.
  • Experimental conditions in a laboratory are difficult to apply to real-world situations, especially when people may be attempting to beat the system.
  • Even if lie detection worked, there are ethical and legal questions regarding the use of these technologies as evidence in a courtroom.

Polygraphs, commonly known as lie detectors, rely on unconscious responses such as heart rate, breathing, blood pressure, and sweating to predict when a person is engaging in deception. These physiological responses due to stress are controlled by the autonomic nervous system, the connections between your brain and most of your internal organs. Because polygraph results can be influenced by the subject’s physiological and psychological state, the skill of the examiner, and the context of the examination, they are generally not considered to be conclusive evidence.


fMRI: The New Lie Detector?
Functional brain imaging offers the possibility of revealing brain activity during the process of fabricating a lie. Several companies offer fMRI lie detection services, and there have been multiple attempts to introduce fMRI lie detection as evidence in criminal trials. How justified is the claim that fMRI offers a more accurate picture of truth telling and deception than polygraphs? Neuroscientists have attempted to answer this question by directing subjects to alternate between telling the truth and telling lies while in an fMRI scanner. Comparing patterns of activity during these two conditions reveals a number of brain areas that are more active in a person during deception. But it’s not that simple.


First, researchers do not agree on precisely which brain areas are activated during deception, and like polygraphs, methodological factors might change experimental conditions. Lab studies might not reflect the emotional context of criminal lie detection. Additionally, some trials may involve psychopathic individuals, who are known to lie frequently and with less effort than neurotypical people. Even if these complications were fixed, recall the challenge of using group data to make individual predictions from Lesson 2 in this unit. Just because the average person has a certain pattern of neural activity when they lie, doesn’t mean that you will have that same pattern when you lie.


The Right to Mental Privacy
The prospect of fMRI lie detection has created societal concerns about self-incrimination, invasions of personal privacy, and the possibility of punishing people for their thoughts rather than their actions. The 5th Amendment to the Constitution protects people from having to testify against themselves, but would it protect people from having their brains scanned against their will? Legal and scientific scholars are still deciding!  While these are important concerns for the future, the reality is that functional brain imaging is (at present) little better than old-fashioned methods. 

Additional Resources
ELABORATE: Self-Incrimination  (45 min)

Explain the following background information to students to frame the following activity:

This activity discusses the 5th Amendment to the Constitution, which protects accused people from being forced to testify against themselves. How might brain imaging factor in?  Could someone be forced to have a brain scan that would be used against them?
Explain to students that when you hear police say “You have the right to remain silent. Anything you say can and will be used against you in a court of law” the suspect is being read their Miranda Rights. Miranda Rights are stated so that the suspect understands that anything they say to police can be used as testimony in court proceedings and their 5th Amendment rights to not testify against themselves.


Guide students through a debate about brain imaging data in the courtroom. This can be framed as either a standard debate or as a fishbowl-type discussion with each side listening and commenting on what the other has just said.

  1. Explain to students that using brain imaging in the courtroom is a bit controversial. How and when should brain imaging data be used in a court proceeding is debatable.
  2. Pose the following case study to frame the debate:
    • A jewelry store in town was recently robbed and security camera footage showed a man breaking in and stealing several valuable necklaces before escaping. One man with a history of theft was found in the neighborhood shortly after the crime was committed and was arrested by police. The suspect matches the general description and appearance of the thief but no fingerprints or physical evidence was left at the crime. While in custody, the police threaten and coerce the suspect into laying still so an fMRI can be performed, in which the suspect is asked many questions about his past criminal history and about this particular crime and the necklaces that have been stolen. The suspect’s lawyer says that the results of the fMRI scan are like testimony and cannot be held against the suspect since he was forced to undergo the scan. The district attorney says that the results of the fMRI scan are like physical evidence, and any physical evidence from the suspect (like fingerprints or hair) that come off his body can be used as evidence.
  3. Divide students into two groups to engage in a debate answering the following question: 
    Should the fMRI brain imaging data in this case study be used in the courtroom as testimony or physical evidence?
    • Group 1 will argue that brain imaging data is like testimony, since it represents your thoughts and feelings and words. 
    • Group 2 will argue that brain imaging data is like physical evidence. If you leave physical evidence behind at a crime scene, the police and the court can use it against you. 

      To assist students in their debate you can provide the following background information:


      Testimony are statements made by defendants in the courtroom and anything the defendant has said since they came into police custody. Defendants are protected from being compelled or forced to disclose the contents of their minds as testimony. This argument can be used to support the idea that you should not be forced to complete an fMRI lie detection scan and any existing fMRI data should not be used against them in court.

      Physical Evidence:

      Some examples of physical evidence are things like blood, DNA, and fingerprints. Physical evidence is defined as a part of the suspect's body or an identifying physical characteristic, such as a handwriting sample. Physical evidence can be used against a suspect in court even without their permission and even if they were unaware that the evidence existed. This can be used to argue that since brain imaging is based on a picture of your physical body and its characteristic activity (not your words or your thoughts precisely) suspects CAN be forced to undergo a brain scan, the contents of which could be used against them.

  4. ​​​​​After the debate ask students to reflect on the following questions:
    • Based on what you’ve learned in this unit, what kinds of results do you think this fMRI scan would provide?  Would they be helpful to either the defense or the prosecution?
    • How did you feel about fMRI data being held against you before this activity?
    • Did this activity change your opinion?  Why or why not?

Lesson 5: Guilt & Responsibility 
Students will explore how damage to brain structure and function affect our ideas of free will, guilt, and responsibility in the courtroom, and how this relates to the insanity defense.

ENGAGE/HOOK: Can The Brain Be Held Responsible?  (10 min)

To introduce this lesson on guilt and responsibility in the brain, read the case study below aloud to students or provide them with a written hand out.

WARNING: This case includes a brief non-detailed mention of sexually deviant behavior and caution is advised.


“Mr. Oft” was a schoolteacher who, despite having no psychiatric history of sexually deviant behavior, became interested in child pornography in middle age and began engaging in inappropriate behaviors towards others, including his own step-daughter. It was later discovered that he had grown a tumor on his right orbitofrontal cortex (abnormalities in this area have been associated with poor impulse control, altered sexual behavior, and sociopathy). When Mr. Oft’s tumor was removed, his pedophilia subsided; later, the tumor grew back, and the urges returned and he began secretly collecting child pornography. Again, the tumor was removed, and Mr. Oft’s urges subsided. 

A midline sagittal cross section and a coronal cross section show the tumor in question covering a large portion of the prefrontal cortex.

Image Credit: Burns JM, Swerdlow RH. Right Orbitofrontal Tumor With Pedophilia Symptom and Constructional Apraxia Sign. Arch Neurol. 2003;60(3):437–440. doi:10.1001/archneur.60.3.437

Ask students to write individual responses to the questions below:

  • Should Mr. Oft be held responsible for his crimes?  Why or why not?  
  • What other thoughts do you have on this case and what factors might be important to consider?
EXPLORE: Are You Your Brain?  (20 min)

Guide students through the following discussion using the steps below:

  1. Pose the following question to students and give some think time: 
    • Where should we draw the line between what is your voluntary behavior and what your brain made you do?  
  2. Allow students to write written responses to the following specific questions, discuss with a partner, and then lead a whole class discussion:
    • If a person with schizophrenia OR a person who was abused as a child kills someone, is one person more or less guilty than the other? Are they more or less guilty than a socially well-adjusted person who was not abused and commits the same crime?
    • Should criminals be held responsible if their brain “made them do it”? What does this mean in the context of neuroscience? Is the brain always responsible for what you do?  Where should we draw the line?
    • How does our knowledge of slow prefrontal cortex development during adolescence change judgments of adolescent culpability? Should a 15-year-old ever be tried as an adult? Does the type of crime matter?
    • Sentencing takes into account both the ideas of retribution and deterrence. How might neuroscience help us understand better whether a criminal is likely to commit a crime again?
EXPLAIN: Mind, Brain, And Responsibility

The following information is teacher-facing and can be utilized to teach students new information in whatever format works best for you and your students.


Key points:

  • In law, the verdict (guilty or not guilty) and sentencing (when the punishment is determined) are two separate phases that can both be affected by neuroscience. 
  • Neuroscientific evidence about brain development or damage could influence determination of guilt, but its impact has been limited.
  • A ‘mitigating factor’ is information or evidence brought to the court that may reduce or lessen a sentence. Neuroscience is playing an increasing role in various mitigating factors related to development, mental illness, and disease.

Free Will and Responsibility
Let’s revisit Mr. Oft from the lesson launch. Should Mr. Oft be held responsible for his crimes even though his tumor influenced his actions? According to the law, he should. Mr. Oft knew what he was doing, and knew that the act was illegal and immoral. At the same time, most people have the intuition that it wasn’t exactly Mr. Oft’s fault—it wasn’t really him, it was his brain. Most people instinctively feel that there is a part of us separate from our physical bodies—a mind, soul, or spirit—that determines conscious behaviors that are carried out freely. In contrast, neuroscience holds that the mind and the brain are one and the same: every thought and feeling has a corresponding brain state, and the mind cannot exist without the brain. As the state of neuroscience progresses, we may one day be able to trace all of the brain patterns that precede a given behavior. Does the fact that behavior can be traced to a ‘cause’ in the brain excuse someone from responsibility? 


Insanity Defense
In criminal law,  the verdict (guilty or not guilty) and sentencing (when the punishment is determined) are two separate phases. Regarding guilt, can neuroscience help us figure out the boundary as to when someone is no longer in charge of their own behavior? The insanity defense allows defendants to argue that they should not be held criminally responsible for their actions due to a mental illness or defect at the time of the offense. Although it is often referenced in media and pop culture, its actual use is relatively limited because the legal standards for establishing the insanity defense can be stringent and differ among jurisdictions. Neuroscientific evidence demonstrating observable impairment (like a tumor or injury) has been a successful basis for the insanity defense in the past. New insights into the different brain structure and function of people diagnosed with psychopathy have raised questions as to whether these traits could justify the insanity defense as well. However, to date such evidence has primarily been used in sentencing rather than determining guilt. 


Mitigating Factors
Mitigating factors are circumstances that, while not justifying or excusing the criminal behavior, are considered to reduce the guilt or responsibility of the offense, and therefore the severity of the punishment. Neuroscience can be used in determination of mitigating factors in sentencing in several ways. Structural or functional brain imaging can be used to evaluate whether cognitive impairment through illness or injury affected the defendant’s mental state. For example, it has been ruled unconstitutional for people with an intellectual disability to be given the death penalty. Neurodevelopmental risk factors, such as age or environmental conditions (see Lesson 2), may be relevant for considering maturity and impulse control. In addition, genetic risk factors for neurological functions such as lower activity in the amygdala or prefrontal cortex, may inform predictions of a defendant’s future risk profile.

Additional Resources
ELABORATE: Defense and Prosecution Arguments   (30 min)

Guide students through the following activity in order to get them thinking deeply about what neuroscience evidence can be used for in the court.

  1. Present each case in the table below to the class in which neuroscientific evidence was used in the courtroom. Assume that the defendant was found guilty, but that sentencing has not yet taken place.
  2. Without revealing the actual sentence, have half of the class work together to write a defense statement based on the evidence and the other half of the class write a prosecution statement against the neuroscience evidence.
  3. Each team will choose one representative to state the defense and prosecution case.
  4. Present the actual decision given by the court and discuss whether the sentence was appropriate.



Anthony Blas Yepez didn’t deny beating an elderly man to death in Santa Fe, New Mexico, six years ago in a fit of rage. But after learning that he had a rare genetic abnormality [affecting chemical function in the brain] linked to sudden violent outbursts, he argued for leniency, saying he wasn’t fully in control of himself when he committed the crime. (NBC News)


Sentence: 22 years in prison (AP News)


An Israeli-American teenager was found guilty in Israel of making about 2,000 hoax bomb threats against Jewish and other institutions in the United States and elsewhere during Donald Trump’s rise to the U.S. presidency in 2016 and 2017… Kadar’s parents have said he has a brain tumor that causes autism and other mental problems, making him unable to understand the nature of his actions. (Reuters)

Sentence: 10 years in prison (BBC News)


Charles Whitman was a 25 year old ex-Marine in 1966 who began complaining of headaches and irrational, violent thoughts. Later that year, he killed his wife and his mother in his home, then climbed the clocktower on the campus of the University of Texas at Austin and shot several people. He left behind a note, asking that someone perform an autopsy on his brain, as he was convinced it would show that something was physically wrong with him. (The Daily Texan)


Sentence: None, as he was killed by Austin police officers, which was his intent, according to the note. Post mortem analysis showed a brain tumor impacting his amygdala and hypothalamus, although experts still don’t agree on how much of his behavior can be explained by the tumor. (The Daily Texan)


For more information about the Neuroscience & Society Curriculum, please contact neuroscience@fi.edu

Neuroscience & Society Curriculum

Launch Lesson  •  Unit 1: Neurons and Anatomy  •  Unit 2: Education and Development  •  Unit 3: Current Methods in Neuroscience  •  Unit 4: Mental Health and Mental Health Conditions  •  Unit 5: Drugs and Addiction  •  Unit 6: Law and Criminology  •  Unit 7: Future Technologies 


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This project was supported by funding from the National Institutes of Health Blueprint for Neuroscience Research under grant #R25DA033023 and additional funding from the Dana Foundation. Its content is solely the responsibility of the authors and does not necessarily represent the official views of NIH or the Dana Foundation.