There is a reciprocal interaction between psychological science and society. Aberrant cognition, affect and behaviour used to be explained by bizarre theories and the treatments were ineffective and inhumane. Each culture has a symptom pool and patients with psychological problems gravitate towards the symptoms that are thought to be a legitimate indication of a mental disorder. Clinical practice is changed by societal changes if these changes influence the symptom pool.

It is important to interpret psychological research with care because:

• Psychology is influenced by society (e.g. more multiple personality disorder diagnoses when it is portrayed more in the media).
• Psychological research is influenced by socio-political biases.
• The context in which researchers work is influenced by the socio-political context.
• Psychological research does not always replicate.

Systematic empirical psychology has led to scepticism regarding adventurous claims. One important function of psychology is debunking nonsense.

Psychological categories are not static but change because of research and societal influences. The categories are prone to subjective conceptions of what these psychological categories hold. Foucault states that scientific categories order society, making these categories political.

Hacking formulates the looping effect of social kinds which states that social kinds can start as arbitrary but acquire causal power in our social system. This occurs for psychological categories because they become part of people’s conceptualization of their own identity (e.g. “I act like this because I have ADHD”). Psychology shapes reality through the label it creates a society adapts to the label, making the label real.

Foucault states that society needs outcasts and mental disorders are used for this goal. Science employs psychology to exert power over the population through surveillance (e.g. psychological tests). Diagnosis of mental disorders steers social reality as people may interpret their behaviour differently after diagnosis. In addition to that, society treats people differently after diagnosis making the category real in a process of social interaction.

Several requirements allow others to evaluate claims and present counter-evidence. These requirements serve as demarcation criteria for science:

1. Knowledge needs to be coherent and cumulative (i.e. cumulative knowledge)
2. Knowledge needs to be made available (i.e. allows for cumulative knowledge).
3. Knowledge needs to be based on prediction and falsification (i.e. no ad-hoc explanations).
4. Knowledge needs to be revised in light of contradictory evidence (i.e. theory can be revised)
5. The exposition of knowledge needs to be clear (i.e. clarity of knowledge).
6. The information-gathering needs to use well-defined and widely accepted methods (i.e. allows for replication).

These requirements make scientific knowledge trustworthy. Scientific racism might exist through hidden racism; advancing one’s race by non-conspicuous biases against other groups.