Nicolas Geeraert in The Conversation:
The academic discipline of psychology was developed largely in North America and Europe. Some would argue it’s been remarkably successful in understanding what drives human behaviour and mental processes, which have long been thought to be universal. But in recent decades some researchers have started questioning this approach, arguing that many psychological phenomena are shaped by the culture we live in.
Clearly, humans are in many ways very similar – we share the same physiology and have the same basic needs, such as nourishment, safety and sexuality. So what effect can culture really have on the fundamental aspects of our psyche, such as perception, cognition and personality? Let’s take a look at the evidence so far.
Experimental psychologists typically study behaviour in a small group of people, with the assumption that this can be generalised to the wider human population. If the population is considered to be homogeneous, then such inferences can indeed be made from a random sample.
However, this isn’t the case. Psychologists have long disproportionately relied on undergraduate students to carry out their studies, simply because they are readily available to researchers at universities. More dramatically still, more than 90% of participants in psychological studies come from countries that are Western, Educated, Industrialised, Rich, and Democratic (W.E.I.R.D). Clearly, these countries are neither a random sample nor representative for the human population.
More here.