Genes, Nature-Nurture Determinism and Freewill

Workshop: Genetics, Nature-Nurture Determinism and Freewill


  • Clarify for students the nature of the debate on determinism and freewill and how this raises questions on the nature and limits of science
  • Introduce students to the notion that non-reductionist/non-deterministic views are compatible with science, by providing them with insights to appreciate the limits of genetic explanations and reconcile them with other approaches to behaviour and personality

The objectives are for students

    • to increase their understanding of cutting edge genetics and behavioural science
    • to develop and apply their analytic, discussion, argumentation and thinking skills
  • to appreciate that some questions are more amenable to scientific methods than others



The point of the workshop is to highlight that two popular explanatory models of personality are inadequate as tools to bring to bear on questions about levels of personal responsibility.

The first popular model is ‘genetic essentialism’ – the idea that that there is ‘a gene for this and a gene for that’ – and that a super-strong gene can be enough to dictate something about a person’s personality.

The second inadequate model is ‘nature-nurture’ – which identifies two drivers for personality – ‘genes’ and ‘environment’. The inadequacy of this model stems in particular from the way we usually think about ‘environment’ – as something outside the person and outside the person’s control.


The rationale for the workshop is to stimulate thought and discussion about reductionist positions that exist/are assumed to exist in science. Genetics has become an area in which reductionist thought holds sway in some quarters amongst scientists but also, more importantly, amongst the general public and in the popular media. Behavioural genetics, which examines genetic and environmental influences on human behaviour, has increasingly risen to public attention with research claiming to have identified the link between genes and complex behaviours such as artistic ability, altruism, sexual orientation, voting patterns, risk taking, happiness, depression and much more.

One such piece of research has focused on the so-called ‘warrior gene’. The ‘warrior gene’ is a part of DNA responsible for the production of the monoamine oxidase (MAOA) enzyme. A lower than average presence of the enzyme was found to be associated with aggressive behaviour, especially in men with a history of abuse during childhood. In the workshop, we discussed two cases, one fictional and one real, in which the ‘warrior gene’ has been used in court to argue that murderers who have the gene should be found not guilty of the crime on the basis that they lack the capacity to control their aggressive behaviour.

We consider the case of Jono – a 13 year old accused of murder. Jono is found to have the warrior gene and he has been abused. Students are asked to take up positions on whether or not Jono can rightly be held responsible for his actions.

We notice that we have a conflict with a dichotomy of positions – most people say that a person has a choice about how to behave – and some say that behaviour is determined.

The next part of the workshop offers a more nuanced model and asks students to consider whether this resolves the dichotomy and difficulties we previously encountered.

We explore the idea that even though human beings are born with certain biological characteristics, our behaviours, personality and feelings vary greatly depending on how we experience the world around us and react to it. We then shrank the gulf between the two contrasting positions ‘choice’ and ‘no choice’ by noticing that a person can choose her or her environment and influence his or her parents and further that ‘environment’ in the way that a scientist uses the word has a much richer meaning than merely ‘surroundings’. It could even include ‘self-nurture’.

With this third model in place – a model that says that humans have a capacity to co-author their own personalities and futures, we agreed that the dichotomy we experienced before is not really such a gulf. Rather the reality in the case of the reductionist and the non-reductionist position looks similar to the outside observer and the interpretation of that reality comes down to metaphysical stances and interpretations and that they are beyond our current scientific knowledge and methods to test.

Finally, we reflected on how these matters are portrayed in both the scientific and popular debate, and we agreed that to reduce such complex questions to straightforward explanations such as “the gene for” is scientifically inaccurate.


Part 1
Why Does It Matter? Genetic, Personality and Behaviour in the Popular Discourse and Imagination

This part of the workshop aims to reveal ‘‘genetic essentialism’ the misconception that genes code directly for traits and that a ‘’super-strength gene’ may be enough to swing a personality one way or another. The intended outcome of this section is that students agree that this is too simple as an account of personality.


Explain to students that genetics is increasingly associated with complex personality traits and behaviours in the popular discourse and imagination. Use example from the media to illustrate the point (examples in PPt)

Draw students’ attention to the language used (e.g. “it’s all in the genes”; “how genes dictate XXX”).

Explain that the idea of one gene for one trait does not reflect the situation for personality – there are lots of genes and lots of other factors to consider.

The idea of one gene for one trait is perhaps sustained because there are a very few diseases such as Huntington’s where a variant of one gene does have a significant effect on health.

Part 2

Nature – nurture OR Nature-nurture-choice

The aim of this section is to widen the discussion to include genetic and environmental factors (nature – nurture) as shaping personality. The intended outcome is for students to notice that for most of the class, this model also doesn’t fit their intuitive explanation of behaviour – as most people also believe behaviour has a degree of choice.

In a typical class, you are likely to find that most students perceive choice to play a role while some argue that behaviour is fully determined by factors external to the person.

Conclude by presenting the supposition that ‘nature-nurture’ does not seem to be adequate if we are looking for a model that encompasses everyone’s positions. The next section will help to demonstrate how unsatisfactory this model (nature-nurture) is.


Ask students to explain how they explain their own personalities (paired discussion)

Call for ideas – highlight ‘nature-nurture’ which is likely to be offered. Drill into what this means – also pick up on the term ‘environment’ if it is offered. Introduce the word ‘upbringing’ or highlight it if offered.

Put two circles on the board – in one put ‘nature/genes’ and in the other ‘nurture/environment/upbringing’. Point to the second circle and ask students to discuss what these factors might be in their groups.

Notice with students that genes and upbringing/nurture/environment are passive (not controlled by the person).

Encourage children to notice that most are not happy with this account – they also want to include ‘choice’ and use the following story to make the point: “Jo’s parents have successful careers in music. Jo’s mother feels Jo is a natural talent and presses Jo daily to practice the piano” Now ask students where do they see ‘nature/genes’ fitting in the story, and where is the ‘nurture’ in the story – then ask, how do we account for Jo’s resistance – is this a third part ‘choice’? (Discussion)

Ask students where choice should fit in – if at all – should it have a third circle? Is it inside one of these two circles?

Optional – you could ask students to consider how this might work for twins in a twin study. We might suppose their personalities are different to some extent – how do we explain this? We know they began with identical genes. Are differences between them due to slight differences in their environments?

Ask students to consider their own personalities and behaviour – and to take up a position on a continuum that has ‘choice’ at one end and ‘determined by factors outside my control’ at the other. This involves physically placing themselves on a line across the classroom. (activity – continuum)

Summarise by proposing that we have a debate – ‘nature-nurture’ or ‘nature-nurture-choice’.

Part 3 Jono
Seeing the muddle in action – the case of Jono


In this main activity, students look at the case of Jono, a fictitious story created by the TV series, ‘Law and Order’ – but based on real science and real law cases.

Present students with the following story:

Jono is a thirteen year old boy under trial for beating a friend of his to death. At the time of the murder, Jono was in foster care after he had been taken away from his family home. His father was in prison for a violent crime, and his mother would often go out at night to drink and leave the young boy alone.

During the trial, it emerges that Jono has the so-called ‘warrior gene’. This is a variant of a gene (MAO-A gene) which scientists have found to be associated with aggressive and anti-social behaviour. Scientists have also found that men who have this variant of the gene are more likely to be aggressive and violent if they have themselves suffered a past of abuse in childhood. Jono, has the so-called ‘warrior gene’ – and his father was also aggressive and the boy suffered a traumatic upbringing.

The lawyer argues that Jono should be found not guilty because the gene has been triggered or strengthened by a history of abuse and has made it impossible for him to control his aggression.

Students bring two models ‘nature-nurture’ and ‘nature-nurture-choice’ to bear in this real case to try to decide how they would rule as a jury – on whether Jono is responsible for his actions.

The aim is for students to see that now that we have the models defined in this way – we have a sharp dichotomy between the two positions – if we define personality as ‘nature-nurture he is not responsible; however if we say that personality has three factors – nature-nurture-choice, then he is. There seems to be no way to resolve this.

Explain that although the judge can take into account Jono’s difficult background – if he responsible he is ‘guilty’ and he will be labelled a criminal. If he could not control his actions – he will be judged ‘not guilty’ on account of his medical condition.

Ask students to discuss and to then take up one of two positions – responsible / not responsible.

Fixing the muddle

In this section, we introduce a third way to understand personality – which draws more carefully on what we know from science.

Once we have this third model we can see that the dichotomy we had before is replaced by one more nuanced understanding.

Students use this new model to rethink Jono’s case – and then to examine how they can understand their own personalities.

Explain to students that the problem is the ‘nature-nurture’ model especially as most people understand it – because it does not reflect the picture as scientists understand it.

Explain that genes are not coding traits – they work at a tiny biological level producing proteins. Some genes control other genes, switching their activity on and off. Very few genes or combinations of genes have a clear-cut directly noticeable effect on how a person turns out. An example of a gene that does have a clear impact is the gene that is linked to Huntington’s disease. The genes that link to personality are far more subtle.

Personality studies that involve genetics are carried out with people who have matured sufficiently to have relatively stable personalities. What you can’t see in the data is the story of how that person arrived at his or her personality. All we know is the person’s genome together with a description of their personality according to some kind of personality assessment tool. What is missing from this picture is that behind this outcome there is a journey of life. Each person is making choices all along the way – choosing who to be friends with, choosing how to spend time, choosing what to watch on TV – in other words people are creating their own environments. Some scholars say that what we feel as choices are better explained as “nature acting on nurture” – so our genetics directs the choices we make. Other scholars say that the choices are influenced by genetics but they are real – so that agency is like the ‘yeast’ in the formation of bread. The yeast has been present all through the journey of life but you can’t pick it out as when you look at the outcome.

As such the gap between the ‘no-choice’ position and the ‘choice’ position is quite subtle – and not something that we can verify either way.

How does this apply to Jono: is Jono responsible for what he did? To ask such question means to ask whether Jono had the possibility to act differently, or whether instead he was compelled to do so. This is a problem that scientists and philosophers have long debated about: the problem of freewill. Freewill means that the person is capable to act freely, and make his/her own choices.

These are two metaphysical positions – and it comes down to how we interpret the outside world we see and what we experience ourselves.


Students use this new model to rethink Jono’s case – Some points that can emerge from the discussion include:

·       How does the gene work?

You can use the background information of the gene to help students appreciate that interactions between different body systems are complex and even if we were able to know and explain all the variables implicated we could not predict the final outcome.

·       What is the environment?

Encourage students to come up with as factors as they can think of – emphasising the way that the person influences their own situation.

Students could examine how this model applies when they try to understand their own personalities.


Part 4: Scientific and other explanations – Michael’s story  
Elucidate different positions on the problem of freewill and help students to appreciate them in relationship to the nature and limits of science. To illustrate this point, ask students to read the following stories.

1)    Scientists have identified a number of genes that are associated with anxiety, and a wide range of factors that interact with these genes.

·       To understand how these interplay with genes, scientists have conducted studies on large samples of population, including on twins (who shared the same genes). By doing so, scientists aim at explaining the different roles that genetic and environmental factors have in predisposing people to anxiety.

2)    Michael struggled with anxiety since he was very little. He spent his childhood in a foreign country and was the only child in his class who did not speak the language. This was a big problem to make friend, and made him very insecure that people might reject him. As a coping strategy, Michael withdrew and became more and more isolated. Michael was very bright, and went on to pursue a degree and a brilliant career. When things got challenging in his life, he would still struggle with anxiety. ‘But I’ve learnt how to deal with it’ said Michael. ‘Sure it can be difficult, but would we give ourselves a fright when we become less than human?’

Ask students in which story we see the person and freewill.

Ø  In the first story the person almost disappears and if don’t think too much about it we might even be led to think that genes and environment are all that exist. This is because science looks at large populations and cannot measure what Michael’s anxiety means to him.

Ø  In the other story, the person is at the centre. We see how Michael makes his own history, albeit not under conditions of his choice.

Both stories are about the same thing and they can both be true.

  Discussion pointers
·        Is one story a better/more valid explanation than the other?

·        Which story is the most helpful explanation for Michael?

·        Was Michael born to be anxious?

·        Can Michael do anything to help his anxiety? Is he destined to always be anxious?

·        Will all people with the same gene variant suffer from anxiety?

·        Will all people who have had Michaels’s early experiences suffer from anxiety?

Discussion: They both offer an explanation for Michael’s anxiety, but in the genes story Michael as a person is absent. Both offer an explanation but not all people with same experiences as Michael will suffer from anxiety. Neither genes nor our upbringing define who we are.

(Explain to students:

·       The two version of the story are different because the story is complex and there are many things going on: genes, brains, peoples, scientists, school environments, etc. Depending on what we focus on, the story can be told in different ways. Reductionism is when we focus on one element of the story alone (e.g. the gene) –we reduce everything to one thing and explain every other element of the story with that.

·       Our understanding of the story can change drastically depending on how it’s told –we had very explanations of the same problem and reached very different conclusions about it! Determinism is when we assume that if we can identify the cause of an event, we can also predict its effect.

·       It is easy to get hooked on the ‘gene for’ kind of argument, but are we missing out on something important when we do so? )

·       End the session by introducing some aspects of the nature of science,

·       How science informs our thinking

·       Questions science cannot resolve

·       FINALLY: what do we think now? Has our thinking changed?

Teacher led. An explanation of how the science works and its limits.




Jono PowerPoint  

Genes, Nature-Nurture Determinism and Freewill Workshop powerpoint