evolutionary psychology Evolutionary psychology is a theoretical approach in psychology that examines cognition and behavior from a modern evolutionary perspective. It seeks to identify human psychological adaptations with regards to the ancestral problems they evolv ...

, people often speak of the four Fs which are said to be the four basic and most primal drives (

motivation Motivation is the reason for which humans and other animals initiate, continue, or terminate a behavior at a given time. Motivational states are commonly understood as forces acting within the agent that create a disposition to engage in goal-dire ...

s or

instincts Instinct is the inherent inclination of a living organism towards a particular complex behaviour, containing both innate (inborn) and learned elements. The simplest example of an instinctive behaviour is a fixed action pattern (FAP), in which a ve ...

) that

animal Animals are multicellular, eukaryotic organisms in the Kingdom (biology), biological kingdom Animalia. With few exceptions, animals Heterotroph, consume organic material, Cellular respiration#Aerobic respiration, breathe oxygen, are Motilit ...

s (including humans) are

evolutionarily Evolution is change in the heritable characteristics of biological populations over successive generations. These characteristics are the expressions of genes, which are passed on from parent to offspring during reproduction. Variation t ...

adapted In biology, adaptation has three related meanings. Firstly, it is the dynamic evolutionary process of natural selection that fits organisms to their environment, enhancing their evolutionary fitness. Secondly, it is a state reached by the po ...

to have, follow, and achieve: ''fighting'', ''fleeing'', ''feeding'' and ''mating'' (the final word beginning with the letter "M" rather than "F" is a reticent allusion to the cruder synonym "

fuck ''Fuck'' is an English-language expletive. It often refers to the act of sexual intercourse, but is also commonly used as an intensifier or to convey disdain. While its origin is obscure, it is usually considered to be first attested to aro ...

"). The list of the four activities appears to have been first introduced in the late 1950s and early 1960s in articles by psychologist

Karl H. Pribram Karl H. Pribram (; ; February 25, 1919 – January 19, 2015) was a professor at Georgetown University, in the United States, an emeritus professor of psychology and psychiatry at Stanford University and distinguished professor at Radford Univers ...

, with the fourth entry in the list being known by terms such as "sex" or occasionally "fornicating", although he himself did not use the term "four Fs". Conventionally, the four Fs were described as adaptations which helped the organism to find food, avoid danger, defend its territory, et cetera. However, in his book ''

The Selfish Gene ''The Selfish Gene'' is a 1976 book on evolution by the ethologist Richard Dawkins, in which the author builds upon the principal theory of George C. Williams's ''Adaptation and Natural Selection'' (1966). Dawkins uses the term "selfish gene ...

'',

Richard Dawkins Richard Dawkins (born 26 March 1941) is a British evolutionary biologist and author. He is an emeritus fellow of New College, Oxford and was Professor for Public Understanding of Science in the University of Oxford from 1995 to 2008. An ath ...

argued that adaptive traits do not evolve to benefit individual organisms, but to benefit the passing on of genes.

Four Fs and vertebrates

In the case of

vertebrate Vertebrates () comprise all animal taxa within the subphylum Vertebrata () ( chordates with backbones), including all mammals, birds, reptiles, amphibians, and fish. Vertebrates represent the overwhelming majority of the phylum Chordata, ...

s, this list corresponds to the motivational behaviours that drive the activity in the

hypothalamus The hypothalamus () is a part of the brain that contains a number of small nuclei with a variety of functions. One of the most important functions is to link the nervous system to the endocrine system via the pituitary gland. The hypothalamu ...

, namely: fighting, fleeing, feeding and sexual functioning. The hypothalamus responds to these motivations by regulating activity in the

endocrine system The endocrine system is a messenger system comprising feedback loops of the hormones released by internal glands of an organism directly into the circulatory system, regulating distant target organs. In vertebrates, the hypothalamus is the neu ...

to release hormones to alter the

behaviour Behavior (American English) or behaviour (British English) is the range of actions and mannerisms made by individuals, organisms, systems or artificial entities in some environment. These systems can include other systems or organisms as wel ...

of the animal. These hormones include

epinephrine Adrenaline, also known as epinephrine, is a hormone and medication which is involved in regulating visceral functions (e.g., respiration). It appears as a white microcrystalline granule. Adrenaline is normally produced by the adrenal glands and ...

(adrenaline) to increase blood flow and heart rate for a sufficient fight-or-flight response, and

ghrelin Ghrelin (; or lenomorelin, INN) is a hormone produced by enteroendocrine cells of the gastrointestinal tract, especially the stomach, and is often called a "hunger hormone" because it increases the drive to eat. Blood levels of ghrelin are highe ...

, which is commonly described as "the hunger hormone".

In other animals

Species from other phyla than vertebrates, such as

arthropod Arthropods (, (gen. ποδός)) are invertebrate animals with an exoskeleton, a Segmentation (biology), segmented body, and paired jointed appendages. Arthropods form the phylum Arthropoda. They are distinguished by their jointed limbs and Arth ...

s and

sponge Sponges, the members of the phylum Porifera (; meaning 'pore bearer'), are a basal animal clade as a sister of the diploblasts. They are multicellular organisms that have bodies full of pores and channels allowing water to circulate through t ...

s, do not possess a hypothalamus. Hormones that influence the behaviour of

insect Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body ( head, thorax and abdomen), three pairs ...

s are excreted by neurosecretory cells (NCS) in the corpora cardiaca. Sponges, despite not having a neurosystem, do show signs of behaviour in response to external stimuli, but not much is known about neuro-sensory mechanisms in sponges and whether they possess all four of these drives.

Related experiments

In order to explore the influences of the hypothalamus as a drive on the four Fs, researchers lesioned the lateral areas of the hypothalamus of rats. This resulted in a reduction in the interest of eating (''feeding''). If these animals were not fed or cared for, they starved to death, even when enough food was present around them. The influence of the hypothalamus is also clear when researchers overstimulated the hypothalamus. When the lateral areas of the hypothalamus were treated with electrical brain stimulation (EBS), the animals would start eating uncontrollably, which resulted in gaining excess weight rapidly. The hypothalamus consists of clusters of highly similarly functioning nerve cells. These nerve cells operate so intimately that signals may get misinterpreted.

Optogenetic Optogenetics is a biological technique to control the activity of neurons or other cell types with light. This is achieved by expression of light-sensitive ion channels, pumps or enzymes specifically in the target cells. On the level of individ ...

stimulation of the ventromedial hypothalamus in male mice resulted in aggressive attacks towards male and female mice. When this area was controlled by silencing the

ventromedial nucleus The ventromedial nucleus of the hypothalamus (VMN, also sometimes referred to as the ventromedial hypothalamus, VMH) is a Nucleus (neuroanatomy), nucleus of the hypothalamus. "The ventromedial hypothalamus (VMH) is a distinct morphological nucleu ...

, mice showed increased interest in mating, showing a relationship between the responses to fighting and fornicating.

References

{{Biology mnemonics Evolutionary biology Science mnemonics

Four Fs and vertebrates

In other animals

Related experiments

See also

References