Beauty is most commonly defined as an intangible quality of objects which makes these objects aesthetically pleasing to see. These objects may include sunsets, landscapes, beautiful humans and creative works of art. Beauty, along with beauty, is also the basis of aesthetic art, one of the most important branches of aesthetics. Art experts usually divide aesthetics in two: the visible and the invisible aesthetics. Visible aesthetics refer to what we can see and the invisible ones refer to what we cannot see.
The visible aspects of beauty are actually determined by two very complex psychological processes. One of these processes concerns how we see the world around us, in terms of the details we notice and the emotional reactions that appear to be the reactions of others. Another process concerns how we interpret the information coming from our eyes and brain to form an image of the external world. Human beings can actually look at the details and actions around them in a whole new way, especially when these actions and details are interpreted by the brain in a visual system composed of nerves and cells, which give rise to a consciousness of beauty and its importance in human life. Aesthetic perception is, therefore, a subjective experience, which has as many components as human perceptions and which depends on the extent of our imagination.
In order to evaluate beauty, different parts of the brain have to be activated: the mirror neuron system, which provides the link between eye movements and facial expressions; the ventral tegmental area, which plays a major role in the interpretation of behavioral reactions; the premotor cortex, which generates specific motor movements; and the periaqueductal grey matter, which constitutes the major output of the brain. While the eye movements monitor the facial expression and the emotional reaction, the other components of this system monitor the position and orientation of the eyes, the movement of the hands, and other movements of the face. Beauty evaluation is also associated with the cognitive processes involved in the recognition of beauty in nature, such as mental rotation of the eyes or mental pictures of flowers and other natural objects. The result is that, depending on the type of stimuli, different parts of the brain may work in different steps to evaluate beauty. Furthermore, some types of facial expressions may be interpreted by more than one subtype of the same circuit, which can lead to an unbalance of activity in several brain regions.
Beauty is not only a subjective idea, as revealed by the social attitudes towards it, but also a physical reality. The desire for beauty, nurtured by certain cultural beliefs about the importance of physical attractiveness and the physical differences between ugly and beautiful people, leads to different standards of beauty throughout the society. Attractive people are more likely to be hired and promoted than the less attractive ones, which leads to an increase in income, putting pressure on people to conform to beauty standards. The perception of beauty also has physiological effects, influencing the secretion of hormones in the body and the regulation of body temperature. Beauty consciousness has also been shown to be positively related to psychological stress, which is known to exacerbate pain and reduce happiness.
To understand the relationship between beauty and fertility it is important to appreciate the influence of both physical and non-physical factors on beauty. The influence of physical attractiveness lies in its association with the reproductive system, where attractive faces are perceived as more appealing than unattractive ones. Pregnant women who have perceived attractive faces as an indicator of their reproductive potential are more likely to have pregnancy than those who have not, indicating that attractiveness serves as a motivation for reproduction in this case as well.
A second biological factor that shapes beauty-judgment involves the relation between the functional architecture of brain regions. People are judged most harshly on the basis of their appearances, and the effects of physical appearance on brain function are well known. The relationship between the visual cortex and the nucleus accumbens is particularly striking, with individuals who are overweight or obese having greater difficulty with judgments of body weight than those who are not overweight or obese. In addition, the orbitofrontal cortex and the periaqueductal grey matter contain areas activated during memory judgment, which makes the visual system an important input to the regulation of appetitive behavior.