Folk science describes ways of understanding and predicting the natural and social world, without the use of rigorous methodologies (see Scientific method

Scientific method

Scientific method refers to a body of techniques for investigating phenomena, acquiring new knowledge, or correcting and integrating previous knowledge. To be termed scientific, a method of inquiry must be based on gathering empirical and measurable evidence subject to specific principles of...

). One could label all understanding of nature predating the Greeks as "folk science".

Folk science is often accepted as "common wisdom" in a given culture, and gets passed on as meme

Meme

A meme is "an idea, behaviour or style that spreads from person to person within a culture."A meme acts as a unit for carrying cultural ideas, symbols or practices, which can be transmitted from one mind to another through writing, speech, gestures, rituals or other imitable phenomena...

s. According to some evolutionary psychologists

Evolutionary psychology

Evolutionary psychology is an approach in the social and natural sciences that examines psychological traits such as memory, perception, and language from a modern evolutionary perspective. It seeks to identify which human psychological traits are evolved adaptations, that is, the functional...

, it may also reflect the output of evolved cognitive processes of the human mind which have been adapted in the course of human evolution

Human evolution

Human evolution refers to the evolutionary history of the genus Homo, including the emergence of Homo sapiens as a distinct species and as a unique category of hominids and mammals...

.

Skeptics

Scientific skepticism

Scientific skepticism is the practice of questioning the veracity of claims lacking empirical evidence or reproducibility, as part of a methodological norm pursuing "the extension of certified knowledge". For example, Robert K...

 often investigate the influence and validity of folk science.

Some examples of folk science

• Naïve physics
  Naïve physics
  Naïve physics or folk physics is the untrained human perception of basic physical phenomena. In the field of artificial intelligence the study of naïve physics is a part of the effort to formalize the common knowledge of human beings....
  
  
• Folk biology
  Folk biology
  Folk biology or folkbiology is the cognitive study of how people classifyand reason about the organic world. Humans everywhere classify animals and plants into obvious species-like groups...
  
  
• Folk psychology
  Folk psychology
  Folk psychology is the set of assumptions, constructs, and convictions that makes up the everyday language in which people discuss human psychology...
  
  
• Physiognomy
  Physiognomy
  Physiognomy is the assessment of a person's character or personality from their outer appearance, especially the face...