Generalizability is the extent to which we can confidently predict the results of a study would apply to a different context, including different people, places, and procedures. When considering the extent to which we can generalize findings from animal studies, we are considering how confidently we could predict the same finding in humans.
For example, animal studies like Sapolsky’s research on baboon’s (read more) have found that lower ranking baboons have higher cortisol levels. But does this mean that low status correlates with high stress? Even “primatologists themselves have warned repeatedly about over-generalizing from primate data to human societies,” (Petticrew and Smith, 2012)
- So you want to assess ecological validity?
- Lesson Idea: Understanding generalizability and population validity
- So you want to assess population validity?
When considering the generalizability of animal research, a good tip is to remember C&C: culture and cognition. Our cultures and cognitive processes are more complex than other animals. Specific differences in this regard could affect generalizability of animal findings. If you can give a good reason how or why our thinking or environment could affect the connection between two variables found in animal studies, it will raise your evaluations beyond the vague generic statements like “this was an animal study so it doesn’t apply to humans.” Such oversimplified statements are not examples of critical thinking.
Let’s look at an example…
Rosenzweig and Bennet (Read More): Environment and Brain Development
This study found that rats living in cages by themselves with just food and water and no other stimulation had less development in their brains compared to rats in cages with social groups, toys and maze training. The conclusion is, therefore, that our environment can affect our brain development and if we’re in deprived environments our brains won’t grow as much. But consider the advanced cognition of humans – we can sit in an isolated room for hours and meditate, or daydream, or use our imaginations. We know that cognition, not just our environment, affects brain development, too. So in some extreme situations, the results might not apply. For example, monks who live rather austere lifestyles but spend hours meditating have more developed PFCs than other people. The animal model, therefore, gives us an insight into possible factors affecting human brain development, but there are situations where this might be limited.
Teacher Tip: When you start writing your own critical thinking examples you’ll find that it invariably relies on using personal knowledge. This is why the themantic model uses a bottom-up approach: building knowledge brick-by-brick before extending students with critical thinking.
Sapolsky (1990) (Read More): Social Status and Stress
Sapolsky found that lower ranking baboons are hypercortisolemic – they have elevated levels of stress hormones. Can you think of ways that human cognition or culture might affect the link between status and stress?
Note: This material has been designed to help students with a critical thinking extension task in our upcoming “Stress” unit for Health Psychology. I’ll update this post with the links when it’s published.
Travis Dixon is an IB Psychology teacher, author, workshop leader, examiner and IA moderator.