Sunday 1 February 2015
I recently read the book, Learning Causality in a Complex World by Tina Grotzer. A book that I feel should get more attention.
So often in our course our students write about “cause and effect relationships.” However, very often the cause and effect is much more complex than they realize. Grotzer argues that there are at least six types of causal relationships: simple, domino, cyclical, spiraling, mutual and relational. She argues that when students can put labels on types of causation, it gives them a schema for better understanding how things work. Unfortunately, most of our students see most relationships as simple causal relationships where x causes y.
Domino causality is defined as cause and effect relationships where the effects become causes and there is a sequential unfolding of effects over time. Often by looking at the simple cause and effect relationship, students miss just how complex things really are.
In the text, she gives several examples. When discussing what would happen if a plant species were to disappear, students tend to focus on the animals that feed on that plant and do not look at how the decrease in the population of that animal due to a shortage of food would have an effect on other populations. Being able to see the chain of reactions is important for a more complex understanding of science.
So, how does this fit into psychology? We have several cases of domino causation which often get students trapped in overly simplistic understandings of psychology. For example, the argument that serotonin deficits cause depression. In this argument, one has to try to determine what are the steps that lead from a serotonin deficit to depression? What does a serotonin deficit do? How does one get a serotonin deficit? When we look at modern research on depression, we find that one of the effects of high levels of cortisol is a lower rate of serotonin production. Does this then cause depression? So, should we be trying to manage stress to lower depression instead of treating low levels of serotonin? Understanding the complexity of the relationship encourages us to ask more complex questions.
Another example is the study by Michael Meany. Many students conclude that a lack of motherly grooming leads to problems with spatial memory. It is actually much more complex than that. The mother rat’s nurturing behavior leads to the activation of the glucocorticoid receptor gene (GR, also known as NR3C1), resulting in lowered stress response. The stress of being taken away from the mother leads to down-regulation of the expression of the GR – that is, the expression of the gene is decreased. This epigenetic effect then leads to an inability for the mice to regulate levels of glucocorticoids. Long term high levels of cortisol lead to hippocampal cell death. This cell death, in term, has an effect on the rats’ ability to recall spatial information.
Getting students to ask what might be the steps that lead up to what they consider to be a cause of a behavior –or to have them consider what effect the effect may have on the behaviour of the individual – is another good way to help our students develop their critical thinking skills. By recognizing the many steps that lead to an ultimate effect, they can realize that there are many points at which an intervention could change behaviour. This also means that the "first cause" is not a "direct cause" of the effect and may actually lead to several other effects. It might make our heads hurt to think about it, but being able to identify domino causality will help students discuss the complex relationships between variables in the study of behaviour.