Humans are a cultural species, this means that people from different cultures live different lives. The unique contribution of cultural psychology is that people from different cultures also differ in their behavior and lifestyle. An important theme within psychology is that psychological processes are formed by experiences. Because people in different cultures have different experiences, we can expect that there are also differences in the ways people think, act and feel. 

Although experiences shape psychological processes, the very base of these processes are neurological structures that are very similar for a lot of people around the world. Thus, the brain makes these differences possible and limits them. Two important questions in cultural psychology therefore are 'To what extent do the people around the world have a similar brain structure with similar psychological processes?' and 'What are the differences of the brain structure related to the cultural differences?'

What is culture?

Culture is any idea, belief, technique, habit, or practice acquired through social learning of others. Cultures are groups of people that exist within some kind of shared context. People in a certain culture are exposed to the same kind of cultural ideas. 

There are a number of limitations when studying the concept of culture:

• The boundaries of culture cannot be clearly defined (e.g. globalization can influence culture).

• Cultures change over time.

• Within a culture there is great variation between individuals.

What are psychological universal traits and abnormalities?

According to Shweder (1990), much in the field of general psychology assumes that people are the same all over the world and that the brain functions according to a number of natural and universal rules that are independent of context and content. Yet there are also many differences between people worldwide. Shweder says that the brain can be seen as a central processing unit (CPU) which operates independently of the content that it is thinking about or of the context within which it is thinking. This is the basic principle of general psychology.

According to the CPU perspective, important cultural variation in ways of thinking does not exist, because cultures only provide variations in context and content which lie outside the operations of the underlying CPU. So, if any cultural differences are found in studies, this is seen as the result of noise such as translation errors.

Cultural psychologists, in contrast with general psychologists, start from the assumption that the mind does not operate completely independently of what it is thinking about. People are cultural beings and their actions, thoughts and feelings are immersed in cultural information. This immersion in cultural information leads to their actions, thoughts and feelings being meaningful. If people are often confronted with a certain idea, the same network of information about the idea is being activated. If the network of information is activated often enough, then it becomes chronically active. Thus, easier to work with compared to networks that are being activated less often. Because cultures differ in the ideas with which they are often confronted, different networks of thoughts, behaviors and feelings will also be most accessible in different cultures. 

The brain can be shaped by different cultural experiences. So have London cab drivers a greater hippocampus (the hippocampus is related to spatial memory in navigation), than the general population (Maguire et al., 200). People with a certain brain structure do not become part of a specific culture, the culture rather forms their brains. 

People are so surrounded by their cultural world that they always behave like cultural actors, and their thoughts are always supported by the meaning that is derived from their culture. So, many cultural psychologists believe that cultural meanings are entangled in our brains and we can not consider the mind to be completely separate from its culture.

Case study: the Sambia

The Sambia, a former warrior, but now peaceful tribe, live in the east of Papua New Guinea. Their culture is very different from Western culture. The Sambia assume that femaleness is an innate natural essence, whereas maleness must be acquired. They call this 'jerungdu': physical power that you are not born with, but that you must acquire. Jerungdu is seen as the supreme essence of masculinity. Sperm is seen as the physical basis of jerungdu. The Sambia think that a boy's body cannot produce sperm on its own; this ability must be acquired. To ensure that the boys start producing sperm, they are subjected to homosexual rituals. When Sambian boys are 7 years old, they satisfy male adolescents and older men orally on a daily basis. When they are 15 years old, the boys produce sperm themselves and this is passed on to younger boys who now satisfy them orally. Until the man conceives children, he displays bisexual behavior. A few years after being married at 17 years old, the man forms an exclusively heterosexual relationship having children together. 

These practices are not only performed by the Sambia, but are also to be found in other cultures, with little variation. Even these variations can initiate feelings of disgust for one culture to the other. Looking back at the example, the men in the Sambia see their sexual activities (homosexual, bisexual and heterosexual) only as behavior. In the Western culture, these sexual activities are not only seen as behavior, but more as a form of identity. Sexual orientation is seen as an important part of identity in Western culture. The difference between Sambia and Western culture also makes it clear that the meaning of a certain behavior is culturally determined.

Psychological universal properties and levels of analysis

If we look at culture and psychology, there are two contrasting views. On the one hand there is the view that psychological processes are essentially the same all over the world and on the other hand there is the view that psychological processes differ between cultures. It is difficult to study through research which opinion is correct. One of the reasons for this is that it is difficult to agree on how to measure universal properties. This creates tension between universal and cultural concepts. The more abstract a concept or custom is described, the more universally it can be perceived. For example, the term "marriage": if it is described as "a sort of formal agreement in which a man and a woman stay together during a relationship," the concept is more universal than when it is described as "a man and a woman fall in love and agree to share their lives until one of them dies or until they get divorced".

Universal properties can be looked at by a number of different levels. Norenzayan and Heine (2005) have developed a decision tree for this. This structure consists of four levels:

1. Nonuniversal. There are also psychological processes that do not occur in all cultures, thus being nonuniversal, and that can be said to be cultural inventions. In the Middle East and in Asia people learn to count with an abacus, a calculation tool. This is called abacus reasoning. They think very differently about numbers compared to people from Western cultures.

2. Existential universal. This is about a psychological phenomenon that exists in multiple cultures, but the phenomenon is not necessarily used to solve the same problem, nor is it equally accessible across cultures. It also does not have to be the same process. An example of this is that in Western cultures success is experienced as motivating and failure as demotivating. The opposite pattern is observed in East Asia: people are motivated to work harder after failure than after success.

3. Functional universal. This means that psychological phenomena exist in multiple cultures, are used to solve the same problems across cultures, but some universal functionalities are more accessible to people from some cultures than others. An example is that of the punishment of people who behave not according to the law. This occurs in many cultures, but in some cultures this is more prevalent. Also, some cultures have stricter penalties on this kind of behavior than other cultures. Yet, the meaning of punishment is the same. 

4. Accessibility universal. This is the strongest case for universality. This means that a given psychological phenomenon exists in all cultures, is used to solve the same problem across cultures and is accessible to the same degree across cultures. For example, physical laws (including the knowledge that objects can not just disappear) or social facilitation (perform better on tasks that are well learned and worse on tasks that are poorly learned if someone else is present). There is not a lot of cultural variability for the understanding of these two concepts.

The psychological database is largely Western

Much research into culture and psychological processes has been done in Western cultures. More than 90 percent of the articles on cultural psychology have been written by Western, mainly North American, institutes. This causes a generalization problem to other cultures, apart from the Western culture. Another limitation of current studies is that the sample, which often consists of bachelor's students in psychology, is not representative of the (global) population. So, much research is done by and with WEIRD societies: Western, educated, industrialized, rich, and democratic societies. 

Cross-cultural data shows that:

• People from industrialized societies have a different response than small-scale societies.

• People from Western societies have more pronounced responses than people from non-Western societies.

• Americans show more extreme responses than other Westerners.

• Responses from college-educated people are different from those of non-college-educated adults.

Why study cultural psychology?

A good reason to learn more about cultural psychology is that if you want to understand the human mind, it is important to investigate the role of cultural experiences in our ways of thinking. It has been made clear several times that results obtained from Western studies do not always apply to samples from other cultures. So, if the role of cultural psychology is not taken into consideration, it results in an incomplete understanding of the human mind. Moreover, the increase in globalization, and with it the advent of a multicultural society, means that we are increasingly coming into contact with people from other cultures. Two approaches are possible when dealing with cultural differences in a multicultural society. The first is the color-blind approach (culture-blind), which means that differences between groups are ignored and it is assumed that everyone is the same. However, research has shown that it is better to emphasize differences and to bring out the best qualities of each culture. The multicultural approach focuses and respects these group differences. By learning more about cultural psychology, we can increase the understanding and appreciation of cultural differences. In this way we can improve the mutual relationships between different cultural groups. When trying to understand how people differ in different cultures, people fare better than when they do not respect the differences.

Are you a product of your own culture?

Your own culture is often invisible to yourself, while other cultures clearly perceive your culture. Other cultures are much clearer for us. For example, you do not hear your own accent, but you can hear that of others.

Our thoughts and behaviors seem natural to us because we do not know how to think or act differently. We can only understand our own culture if we can compare it with other cultures.

It is important not to condemn other cultures because they are different. Ethnocentrism means that we condemn people from other cultures by comparing them to the standard of our own culture.