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Morality and the Brain - a Lesson Plan in progress

adiflesher's picture

The following is a lesson plan for high school students about morality and the brain.  The lesson can be taught in the context of a larger curriculum about the brain or can stand alone.  The focus of the lesson is to give the students insight into moral decision making and to raise questions about the ways they make moral decisions.

I’ve tried to keep the lesson itself relatively simple and geared towards big questions.  Since many of these questions remain the topic of scholarly debate I’ve included some links detailing some of this dialogue. 

Please add comments on how you think this lesson can be improved or fleshed out. I hope to use this lesson in the upcoming year in High Schools around the city of Philadelphia.

I am still in the process of adding parts to the lesson, fleshing it out and adding the appropriate footnotes.

Morality:  Pull the lever or push the fat guy and other dilemmas that will have you scratching your brain about the nature of morality.   


  • Students will explore Morality through the lens of brain science
  • Students will experience and discuss the process of moral decision making
  • Students will learn about some of the things the brain does when dealing with moral dilemmas.
  • Students will reflect on the experience of making moral decisions and how they make (and want to make) moral decisions in their lives.  


You are standing next to a train track.  Suddenly you realize that a train is heading down the track  towards 5 railroad workers. You cannot shout to warn them. The only way that you can save their lives is to pull a level that will re-direct the train down another track. On this second track there is a single railroad worker. If you pull the lever the single railroad worker will die. If you do not 5 railroad will die. There are no other choices. What do you do? 

Trolley Problem

Read this dilemma to your students and show them the accompanying slide (it helps to have the visual) Have students debate about what the right thing to do is.  After approximately 3-5 minutes of debate ask the class to vote on the right thing to do.

Now pose a second scenario:

Trolley Problem Fat guy

The train is heading down the track. Now there is only one track. There is a very big guy standing on a bridge above the track. The only way you can save the men on the track is by pushing the big guy. You cannot jump in front of the track yourself. You cannot warn the workers. Do you do it?

Show the second slide  of the Trolley Dilemma. Explain the dilemma. Repeat the debate.  Why is the situation in the first slide different than the situation in the second slide. Again have the class vote on the right thing to do. Have somebody from both sides explain why they chose the way they did.

Now explain the background of the Trolley Dilemma.  Be sure to point out that in almost every case where this scenario is tested people tend to choose overwhelmingly to pull the lever, but overwhelmingly not to push the fat guy.  (This may be somewhat affected in their case, by priming them to push the guy, by first asking them the lever question, but in most cases the class will choose not to push the guy).

The Brain and Morality:

The trolley problem as it is known is an old philosophical problem. You can read more about the history of this problem and debate it has caused in philosophical circles here. The bottom line is that most people (about 85%) choose to pull the lever, while most people choose to not push the man. 


It is interesting to note the answers that your students come up with. Some of the answers philosophers offered are:

“One clear distinction is that in the first case, one does not intend harm towards anyone - harming the one is just a side-effect of switching the trolley away from the five. However, in the second case, harming the one is an integral part of the plan to save the five. This is an argument Shelly Kagan considers, and ultimately rejects, in The Limits of Morality[7]So, some claim that the difference between the two cases is that in the second, you intend someone's death to save the five, and this is wrong, whereas in the first, you have no such intention. On the other hand, Thomson argues that an essential difference between the original trolley problem and this version with the fat man, is that in the first case, you merely deflect the harm, whereas in the second case, you have to do something to the fat man to save the five. Thomson says that in the first case, nobody has any more right than anyone else not to be run over, but in the second case, the fat man has a right not to be pushed in front of the trolley.”

A recent generation of researchers began to ask what is going in the brain during this reasoning. Recently Joshua Greene a young professor at Harvard began running a new version of the trolley problem. He asked people the same questions, but instead of just noting the results he had them sit in fMRI machine while they answered. He found that when people answered the first question they had increased activity in the dorsolateral prefrontal cortex – an area of the brain associated with logic and reasoning. When people were asked the second question they had increased activity in the medial frontal cortex and area associated with emotion. (

This type of research led Jonathan Haidt to revist the question of moral philosophy. Haidt argued that the old school of moral philosophers and psychologists had it wrong. Morality for most people wasn’t about rational decisions, rather it was primarily and emotional response.   Haidt made this argument in a paper called “The Emotional Dog and Its Rational Tail”

He pointed out that in many cases people make quick emotional decisions and then use reason to support the decision they have already reached. 

So where do morals come from? 

Do animals have morals?


"I've argued that many of what philosophers call moral sentiments can be seen in other species. In chimpanzees and other animals, you see examples of sympathy, empathy, reciprocity, a willingness to follow social rules. Dogs are a good example of a species that have and obey social rules; that's why we like them so much, even though they're large carnivores."[3]

Why do we behave badly?


Phineas Gage -

Is brain injury related to bad behavior. The answer seems to be yes. About 8.5% of the population reports having suffered a traumatic brain injury. Between 25% and 87% ( of inmates report a TBI..


Is a brain injury and excuse for behaving badly?

Nice Shoes:

Lets say you just bought yourself a pair of $200 shoes that your really, really wanted. You are walking down the street with your brand new shoes and suddenly you pass a pond where a baby is drowning. You can jump in and save the baby, but you will ruin your $200 shoes (no you don’t have time to take them off).  What do you do?

After this dilemma is debated ask the following dilemma.

You receive a letter in the mail from an organization you trust. There is a tragic drought in Africa.  People are starving. A donation of $36 dollars will save a child’s life. Do you give the money?


Martin Mellish's picture

Cross-cultural research using the Trolley Problem in schools

HI there,

My name is Martin Mellish, and I am a teacher at Number 7 High School in Chengdu, China. This Spring I facilitated a class on the Trolley Problem and related ethical dilemmas for a group of 600+ Chinese high school students. Data collected include about 11 hours of videoed discussion and 561 completed questionnaires, including answers to the Trolley problem and 20 related questions and comments on the answers.

Whereas Western participants tend overwhelmingly to turn the trolley, the majority of these students chose NOT to, by a highly statistically significant margin ( p = 0.0007 ). Some responses can be viewed at

These students' comments, and their answers to the other questions, make clear that the majority of the difference can be accounted for by the fact that many students did not feel they had moral agency (i.e. a right to intervene) in the situation. Their answers further indicate that this feeling arises due to a difference in underlying social contract.

The Western social contract is of the type suggested by John Locke (and incorporated into the American Declaration of Independence) that maximizes individual freedom of action. However, the Chinese social contract limits individual freedom of action in exchange for security and stability. This has been the default social contract in China since the end of the Warring States period in 200 BC. In the West, we associate this Chinese-type social contract with the name of Thomas Hobbes ('Leviathan') .

Just as the Western Lockean social contract is underpinned by ideas about individual autonomy that ultimately derive from Protestant theology, the Chinese social contract is underpinned by Daoist, Buddhist, and folk beliefs to the effect that it is wrong to attempt to interfere with Destiny, God's plan, or the way of Nature. Religious considerations played an astonishingly large part in students' thinking, especially considering that China is nominally an atheist state (for example, 54 students left comments specifically mentioning God).

I have a lot of materials that might potentially be of interest to you , including recorded student discussions, answers to the questionnaire and statistical analysis thereof, and the Powerpoint presentation I used to prime the discussion. If you'd like me to send you any of them, just ask.

Also: I am looking to make contact with a school that plans to present the Trolley Problem in class, and would be prepared to have the students answer an on-line questionnaire on it that would take about half an hour, in the interests of cross-cultural research on the basis of morality. If you know of any such school, it would be great if you could put us in touch. My email is

Best wishes and thanks,

Martin Mellish.

Julie Herskovitz's picture



My name is Julie Herskovitz and I was apart of the ACAJE conference this past Thursday, 11 December, outside Philadelphia. I am the English teacher who made the funny, albeit inappropriate, comma comment. I did not mean any disrespect; it is habit thet when asked if anything is wrong with a sentence my mind goes to grammar.

I wanted to let you know that I found what you were saying fascinating and am sorry your time was cut short; I would have loved to have heard you speak more.

I just wanted to pass along my comments and thank you for the fun and engaging presentation on Thursday as well as the info-packed web site to explore.

Best of luck to you.
Julie Herskovitz