its not really a matter of who "discovered" the instinct theory but who PROPOSED the instinct theory is what i think your question is asking in which case i believe the answer--if my memory serves me right-- is William McDougall
Instinct theory is a theory that looks at motivation of people and animals. In instinct theory, behavior is motivated by instinct, which is ingrained in animals to help them survive.
Instinct theory is a belief in psychology that instinct provides humans with the motivation to do certain actions and behave in a specific manner. Instinct theory was good at explaining why, for example, babies root onto their mother's nipple for milk. However, it didn't have much credence when it came to explaining our other behaviors. Instinct theory has been supplemented by drive-reduction theory, and arousal theory, both of which also try to explain motivation.
The cast of Instinct Theory - 2004 includes: LeeAnne Hutchison as Woman Adam Rothenberg as Man
Instinct Theory - 2004 was released on: USA: 18 June 2004 (Triggerstreet.com Online Film Festival)
Albert Einstein discovered the theory of relativity
Instinct theory in psychology suggests that certain behaviors are innate and driven by biological instincts. An example of this is the instinct of a mother to protect her child, which is believed to be a natural and instinctual behavior that is not learned but rather inherited.
keep oneself safe
The concept of instinct in motivation theory was replaced by the concept of drive theory. Drive theory suggests that internal physiological needs create a state of tension or arousal that motivates individuals to act in ways that reduce this tension and restore homeostasis.
Instinct theory in psychology suggests that certain behaviors are innate and driven by biological instincts. These instincts are thought to be inherited and guide behaviors such as aggression, mating, and survival. Instinct theory posits that these instincts influence human behavior by providing a foundation for understanding and responding to the environment in ways that promote survival and reproduction.
instinct approaches to motivation are most apparent in the theory of evolutionary psychology, which suggests that motivations are driven by survival and reproduction instincts that have evolved over time.
Genic balance theory is discovered by american scientist Calvin Blackman Bridges
Instinct theory claims that how people survive and survived is related to generics. Evolutionary perspective claims looks at how previous language, memory, physical characteristics, etc. have evolved over time. While evolutionary perspective deals with biology more, it could technically fall under instinct theory because of how they both look at human behavior.