Folk psychology, commonsense psychology, or naïve psychology is the ordinary, intuitive, or non-expert understanding, explanation, and rationalization of people's behaviors and mental states. In philosophy of mind and cognitive science, it can also refer to the academic study of this concept. Processes and items encountered in daily life such as pain, pleasure, excitement, and anxiety use common linguistic terms as opposed to technical or scientific jargon. Folk psychology allows for an insight into social interactions and communication, thus stretching the importance of connection and how it is experienced.

Traditionally, the study of folk psychology has focused on how everyday people—those without formal training in the various academic fields of science—go about attributing mental states. This domain has primarily been centered on intentional states reflective of an individual's beliefs and desires; each described in terms of everyday language and concepts such as "beliefs", "desires", "fear", and "hope".

Belief and desire have been the main idea of folk psychology as both suggest the mental states we partake in. Belief comes from the mindset of how we take the world to be while desire comes from how we want the world to be. From both of these mindsets, our intensity of predicting others mental states can have different results.^{[citation needed]}

Folk psychology is seen by many psychologists from two perspectives: the intentional stance or the regulative view. The regulative view of folk psychology insists that a person's behavior is more geared to acting towards the societal norms whereas the intentional stance makes a person behave based on the circumstances of how they are supposed to behave.

When perceiving, explaining, or criticizing human behaviour, people distinguish between intentional and unintentional actions. An evaluation of an action as stemming from purposeful action or accidental circumstances is one of the key determinants in social interaction. Others are the environmental conditions or pre-cognitive matters. For example, a critical remark that is judged to be intentional on the part of the receiver of the message can be viewed as a hurtful insult. Conversely, if considered unintentional, the same remark may be dismissed and forgiven.

The folk concept of intentionality is used in the legal system to distinguish between intentional and unintentional behavior. When looking at an individual, there is an unconventional way of explaining behavior in law. By looking at behaviors and expressions, folk psychology is used to predict behaviors that have been acted out in the past.

The importance of this concept transcends almost all aspects of everyday life: with empirical studies in social and developmental psychology exploring perceived intentionality's role as a mediator for aggression, relationship conflict, judgements of responsibility blame or punishment.

Recent empirical literature on folk psychology has shown that people's theories regarding intentional actions involve four distinct factors: beliefs, desires, causal histories, and enabling factors. Here, beliefs and desires represent the central variables responsible for the folk theories of intention.