In physical attractiveness studies, averageness describes the physical beauty that results from averaging the facial features of people of the same gender and approximately the same age. [1] [2] [3] [4] The majority of averageness studies have focused on photographic overlay studies of human faces, in which images are morphed together. The term "average" is used strictly to denote the technical definition of the mathematical mean. An averaged face is not unremarkable, but is, in fact, quite good looking.[ citation needed ] Nor is it typical in the sense of common or frequently occurring in the population, though it appears familiar, and is typical in the sense that it is a good example of a face that is representative of the category of faces. [2]
A possible evolutionary explanation for averageness is koinophilia, in which sexually-reproducing animals seek mates with primarily average features, because extreme and uncommon features are likely to indicate disadvantageous mutations. [5] [6] [7]
The effect was first described in 1878 by Francis Galton. He had devised a technique called composite photography, which he believed could be used to identify 'types' by appearance, which he hoped would aid medical diagnosis, and even criminology through the identification of typical criminal faces. [8] Galton's hypothesis was that certain groups of people may have common facial characteristics. To test the hypothesis, he created photographic composite images of the faces of vegetarians and criminals to see if there was a typical facial appearance for each. Galton overlaid multiple images of faces onto a single photographic plate so that each individual face contributed roughly equally to a final composite face. The resultant "averaged" faces did little to allow the a priori identification of either criminals or vegetarians, failing Galton's hypothesis. However, unexpectedly Galton observed that the composite image was more attractive than the component faces. Galton published this finding in 1878, [9] and also described his composite photography technique in detail in Inquiries in Human Faculty and its Development. [8]
Similar observations were made in 1886 by Stoddard, who created composite faces of members of the National Academy of Sciences and graduating seniors of Smith College. [10]
This phenomenon is now known as "averageness-effect", that is, high physical attractiveness tends to be indicative of the average traits of the population.
Despite the novelty of these findings, Galton and Stoddard's observations were forgotten for over a century.
In 1990, one of the first computer-based photographic attractiveness rating studies was conducted. During this year psychologists Langlois and Roggman wanted to systematically examine whether mathematical averageness is linked with facial attractiveness. [1] [2] [3] [11] [12] [13] [14] To test this, they selected photographs of 192 young male and female white faces; each of which was computer scanned and digitized. They then made computer-processed composites of each image, as 2-, 4-, 8-, 16-, and 32-face composites, averaged by pixel. These faces, as well as the component faces, were rated for attractiveness by 300 judges on a 5-point Likert scale (1 = very unattractive, 5 = very attractive). The 32-composite face was the most visually attractive of all the faces. [1]
Many studies, using different averaging techniques, including the use of line drawings [15] and face profiles, [16] have shown that this is a general principle: average faces are consistently more attractive than the faces used to generate them. [17] [18] [19] [20] Furthermore, if a female composite (averaged) face made of 32 different faces is overlain with the face of an extremely attractive female model, the two images often line up closely, indicating that the model's facial configuration is very similar to the composite's. [21] See, for example, the illustration of Jessica Alba on the right. [18] [19]
This principle transcends culture. For instance, Coren Apicella and her co-workers from Harvard University [22] created average faces of an isolated hunter-gatherer tribe of 1,000 in Tanzania, Africa, the Hadza people. Hadza people rated the averaged Hadza faces as more attractive than the actual faces in the tribe. While Europeans also rated average Hadza faces as attractive, the Hadza people expressed no preference for average European faces. Apicella [22] attributes this difference to the wider visual experiences of the Europeans, as they had been exposed to both Western and African faces. Thus the indifference of the Hadza towards average European faces could have been the result of lacking the European norm in their visual experience. [23] These results suggest that the rules for extracting attractive faces are culture-independent and innate, but the results of applying the rules depend on the environment and cultural experience. [19] [24]
That the preference for the average is biological rather than cultural has been supported by studies on babies, who gaze longer at attractive faces than at unattractive ones. [25] [26] [27] Furthermore, Mark Stauss [28] reported that 10-month-old children respond to average faces in the same way as they respond to attractive faces, and that these infants can extract the average from simply drawn faces consisting of only 4 features. Adam Rubenstein and coworkers [29] showed that already at six months of age, children not only treat average faces the same as they treat attractive faces, but they are also able to extract the central tendency (i.e. the average) from a set of complex, naturalistic faces presented to them (i.e. not just the very simple 4-features faces used by Strauss). Thus the ability to extract the average from a set of realistic facial images operates from an early age, and is therefore almost certainly instinctive. [28] [29]
Despite these findings, David Perrett and his colleagues [24] found that both men and women considered that a face averaged from a set of attractive faces was more appealing than one averaged from a wide range of women's faces, aged 20–30 years. When the differences between the first face and the second face were slightly exaggerated the new "exaggerated" (or "caricaturized") face was judged, on average, to be more attractive still. Although the three faces look very similar, the so-called "exaggerated face" looks younger: a slimmer (less wide) face, and larger eyes, than the average face. It also had a narrower lower jaw and smaller nose-to-mouth, and nose-to-chin distances than the average face. Since the same results were obtained using Japanese subjects and viewers, these findings are probably culture-independent, indicating that people generally find youthful average faces [30] sexually the most attractive. [24]
The explanation for the averageness phenomenon covers two distinct, but complementary fields of inquiry: cognitive and developmental psychology, and evolutionary biology. [1] [14]
Darwin's (1859) theory of natural selection states that advantageous characteristics replace their less advantageous counterparts, to become the dominant characteristics of the population. [31] [32] Mate-seeking individuals would therefore be expected to preferentially choose individuals with a minimum of unusual features, or, stated differently, individuals whose characteristics are all close to the mean of the population. These individuals are the least likely to carry harmful mutations. [5] [14] This form of mate choice is known as koinophilia, [6] [7] which explains why, what humans determine to be a beautiful face, is a face that contains no extreme features.
Adults and infants organize and consolidate sensory information into categories (e.g. "trees", "chairs", "dogs", "automobiles", "clouds" etc.). Cognitive averaging of the individual exemplars within a category creates a "prototype", or central representative of the category. Thus after seeing several exemplars from a category both adults and infants respond to an averaged representation of those exemplars as if it were familiar. That is, they show evidence of forming mental prototypes, on which they then rely to recognize new instances of the category.
In addition, prototypes are also often preferred to individual exemplars of the stimuli categories. [33] [34] Thus an average face is probably attractive simply because it is prototypical.
If prototypes and cognitive averaging are used by infants and adults to organize and consolidate incoming information [35] [36] people may form a common prototype of faces representing the central tendency of the population very early in life. Fifteen minute-old neonates show no preference for attractive faces over unattractive faces. [14] [26] But 72 hours later they already stare longer at faces judged by adults to be attractive than they do at unattractive faces. [26] This rapid development of an appreciation of facial beauty (as judged by adults) might be explained by the fact that an averaged face made of 32 faces looks almost indistinguishable from any other 32-face averaged face even when they are created from a completely different set of individuals. [1] [2] It is thus possible that an average of only 32 facial exemplars is sufficient to approximate the population mean, and thus produce a prototype that is shared by almost everyone in a community. Kalakanis estimated that newborns see between 5 and 10 faces before they leave hospital in the USA. [37] Thus, after 72 hours, they will have abstracted a prototypical face that is very close to the community's norm. Faces are an important class of visual stimuli for humans, and the perception of "faceness" is a critical part of social responsiveness. Because of the importance of the information conveyed by faces for social interaction, [23] humans should therefore have innate preferences for them as a category, with its associated prototype. This prototype's special attractiveness (over the attractiveness of, for instance, the prototypical "chair") is probably related to the evolutionary importance of the mutant-freeness that the prototypical face represents. [1] [6] [14]
It has been argued that composite faces are more symmetrical than their original images, and that it is this that accounts for their attractiveness. [38] [39] [40] [41] Symmetry is thought to be preferred because it possibly indicates developmental stability in a changing environment, which would be an indicator of genetic quality in an individual. Developmental stability is the ability of an organism to buffer its development against environmental or genetic disturbances and produce a specific phenotype. If individuals are not of high genetic quality, they may not be able to buffer their development against environmental fluctuations and this would result in asymmetries. Thus symmetry may serve as an honest signal of mate quality in both humans and animals. [42] [43] [44] However Langlois, Roggman and Musselman [2] found that when faces were divided down the middle two perfectly symmetrical faces could be created from the two halves, a "left face" consisting of the left half of the face and its mirror image, and a "right face" constructed in a similar manner. These two perfectly symmetrical faces could then be compared with the unaltered face. In all cases, except in the most unattractive original faces, the unaltered face was rated as more attractive than either of the perfectly symmetrical faces. Furthermore, when photographs of faces in profile were used (in which there is no symmetry between the front and back of the head) the average of these photographs was consistently judged to be the most attractive. [16] [45] Symmetry is therefore simply a component of an average face without being the primary or dominant contributor to the attractiveness of the composite face.
Beauty is commonly described as a feature of objects that makes them pleasurable to perceive. Such objects include landscapes, sunsets, humans and works of art. Beauty, art and taste are the main subjects of aesthetics, one of the fields of study within philosophy. As a positive aesthetic value, it is contrasted with ugliness as its negative counterpart.
The face is the front of an animal's head that features the eyes, nose and mouth, and through which animals express many of their emotions. The face is crucial for human identity, and damage such as scarring or developmental deformities may affect the psyche adversely.
The physical attractiveness stereotype, commonly known as the "beautiful-is-good" stereotype, is the tendency to assume that physically attractive individuals, coinciding with social beauty standards, also possess other desirable personality traits, such as intelligence, social competence, and morality. The target benefits from what has been coined as “pretty privilege”, namely social, economic, and political advantages or benefits. Physical attractiveness can have a significant effect on how people are judged in terms of employment or social opportunities, friendship, sexual behavior, and marriage.
Interpersonal attraction, as a part of social psychology, is the study of the attraction between people which leads to the development of platonic or romantic relationships. It is distinct from perceptions such as physical attractiveness, and involves views of what is and what is not considered beautiful or attractive.
Physical attractiveness is the degree to which a person's physical features are considered aesthetically pleasing or beautiful. The term often implies sexual attractiveness or desirability, but can also be distinct from either. There are many factors which influence one person's attraction to another, with physical aspects being one of them. Physical attraction itself includes universal perceptions common to all human cultures such as facial symmetry, sociocultural dependent attributes, and personal preferences unique to a particular individual.
Cuteness is a type of attractiveness commonly associated with youth and appearance, as well as a scientific concept and analytical model in ethology, first introduced by Austrian ethologist Konrad Lorenz. Lorenz proposed the concept of baby schema (Kindchenschema), a set of facial and body features that make a creature appear "cute" and activate ("release") in others the motivation to care for it. Cuteness may be ascribed to people as well as things that are regarded as attractive or charming.
Facial symmetry is one specific measure of bodily symmetry. Along with traits such as averageness and youthfulness, it influences judgments of aesthetic traits of physical attractiveness and beauty. For instance, in mate selection, people have been shown to have a preference for symmetry.
A psychological adaptation is a functional, cognitive or behavioral trait that benefits an organism in its environment. Psychological adaptations fall under the scope of evolved psychological mechanisms (EPMs), however, EPMs refer to a less restricted set. Psychological adaptations include only the functional traits that increase the fitness of an organism, while EPMs refer to any psychological mechanism that developed through the processes of evolution. These additional EPMs are the by-product traits of a species’ evolutionary development, as well as the vestigial traits that no longer benefit the species’ fitness. It can be difficult to tell whether a trait is vestigial or not, so some literature is more lenient and refers to vestigial traits as adaptations, even though they may no longer have adaptive functionality. For example, xenophobic attitudes and behaviors, some have claimed, appear to have certain EPM influences relating to disease aversion, however, in many environments these behaviors will have a detrimental effect on a person's fitness. The principles of psychological adaptation rely on Darwin's theory of evolution and are important to the fields of evolutionary psychology, biology, and cognitive science.
Human male sexuality encompasses a wide variety of feelings and behaviors. Men's feelings of attraction may be caused by various physical and social traits of their potential partner. Men's sexual behavior can be affected by many factors, including evolved predispositions, individual personality, upbringing, and culture. While most men are heterosexual, there are minorities of homosexual men and varying degrees of bisexual men.
The fusiform face area is a part of the human visual system that is specialized for facial recognition. It is located in the inferior temporal cortex (IT), in the fusiform gyrus.
The psychology of art is the scientific study of cognitive and emotional processes precipitated by the sensory perception of aesthetic artefacts, such as viewing a painting or touching a sculpture. It is an emerging multidisciplinary field of inquiry, closely related to the psychology of aesthetics, including neuroaesthetics.
Koinophilia is an evolutionary hypothesis proposing that during sexual selection, animals preferentially seek mates with a minimum of unusual or mutant features, including functionality, appearance and behavior. Koinophilia intends to explain the clustering of sexual organisms into species and other issues described by Darwin's dilemma. The term derives from the Greek word koinos meaning "common" or "that which is shared", and philia, meaning "fondness".
The cross-race effect is the tendency to more easily recognize faces that belong to one's own racial group, or racial groups that one has been in contact with. In social psychology, the cross-race effect is described as the "ingroup advantage," whereas in other fields, the effect can be seen as a specific form of the "ingroup advantage" since it is only applied in interracial or inter-ethnic situations. The cross-race effect is thought to contribute to difficulties in cross-race identification, as well as implicit racial bias.
Sexual selection in humans concerns the concept of sexual selection, introduced by Charles Darwin as an element of his theory of natural selection, as it affects humans. Sexual selection is a biological way one sex chooses a mate for the best reproductive success. Most compete with others of the same sex for the best mate to contribute their genome for future generations. This has shaped human evolution for many years, but reasons why humans choose their mates are not fully understood. Sexual selection is quite different in non-human animals than humans as they feel more of the evolutionary pressures to reproduce and can easily reject a mate. The role of sexual selection in human evolution has not been firmly established although neoteny has been cited as being caused by human sexual selection. It has been suggested that sexual selection played a part in the evolution of the anatomically modern human brain, i.e. the structures responsible for social intelligence underwent positive selection as a sexual ornamentation to be used in courtship rather than for survival itself, and that it has developed in ways outlined by Ronald Fisher in the Fisherian runaway model. Fisher also stated that the development of sexual selection was "more favourable" in humans.
Mate preferences in humans refers to why one human chooses or chooses not to mate with another human and their reasoning why. Men and women have been observed having different criteria as what makes a good or ideal mate. A potential mate's socioeconomic status has also been seen important, especially in developing areas where social status is more emphasized.
Developmental homeostasis is a process in which animals develop more or less normally, despite defective genes and deficient environments. It is an organism's ability to overcome certain circumstances in order to develop normally. This can be a circumstance that interferes with either a physical or mental trait. Many species have a specific norm, where those who fit that norm prosper while those who don't, don't survive or find it difficult to thrive. It is important that the animal be able to interact with the other group members effectively. Animals must learn their species' norms while they're young to live a normal, successful life for that species.
The cheerleader effect, also known as the group attractiveness effect or the friend effect, is a proposed cognitive bias which causes people to perceive individuals as 1.5–2.0% more attractive in a group than when seen alone. The first paper to report this effect was written by Drew Walker and Edward Vul, in 2013.
Mate value is derived from Charles Darwin's theory of evolution and sexual selection, as well as the social exchange theory of relationships. Mate value is defined as the sum of traits that are perceived as desirable, representing genetic quality and/or fitness, an indication of a potential mate's reproductive success. Based on mate desirability and mate preference, mate value underpins mate selection and the formation of romantic relationships.
Neoteny is the retention of juvenile traits well into adulthood. In humans, this trend is greatly amplified, especially when compared to non-human primates. Neotenic features of the head include the globular skull; thinness of skull bones; the reduction of the brow ridge; the large brain; the flattened and broadened face; the hairless face; hair on the head; larger eyes; ear shape; small nose; small teeth; and the small maxilla and mandible.
The ovulatory shift hypothesis holds that women experience evolutionarily adaptive changes in subconscious thoughts and behaviors related to mating during different parts of the ovulatory cycle. It suggests that what women want, in terms of men, changes throughout the menstrual cycle. Two meta-analyses published in 2014 reached opposing conclusions on whether the existing evidence was robust enough to support the prediction that women's mate preferences change across the cycle. A newer 2018 review does not show women changing the type of men they desire at different times in their fertility cycle.