Sexual selection can only influence features that potential mates can perceive, such as smell, audition (e.g. song) and vision. Such features might be reliable indicators of hidden fitness parameters such as a good immune system or developmental stability. It has been argued that more symmetric faces are preferred because symmetry might be a reliable sign of such hidden fitness parameters. However it is possible that high facial symmetry in an individual is not due to their superior genetics but due to a lack of exposure to stressors during development.It has been found that more symmetrical faces are rated as healthier than less symmetrical faces. Indeed, facial symmetry was found to be positively associated with the perceived healthiness of the facial skin. Also, facial asymmetry was found to be correlated with physiological, psychological and emotional distress.Some evidence suggests that face preferences in adults might be correlated to infections in childhood. See also
Beauty
Symmetry in nature
Patterns in nature
Physical attractiveness

References
External links
FaceResearch – Online studies on facial symmetry by researchers affiliated with University of Aberdeen (Scotland) School of Psychology, and University of St. Andrews (Scotland). "A facial symmetry plugin for the GIMP"—Try experimenting with facial symmetry, using open source software. "Psychological Image Collection at Stirling (PICS) Free Database of pictures of faces
"FaceBase An interdisciplinary research consortium for facial symmetry
"Tübinger Face Database An open research database of 200 merged 3-D faces
"A facial symmetry app for iPhone Experiment with facial symmetry, using a free iPhone app.
This offence is created by section 20 of the Offences against the Person Act 1861. Causing grievous bodily harm with intent
Also referred to as "wounding with intent". This offence is created by section 18 of the Offences against the Person Act 1861.Other aggravated assault charges refer to assaults carried out against a specific target or with a specific intent:

Assault with intent to rob
The penalty for assault with intent to rob, a common law offence, is provided by section 8(2) of the Theft Act 1968. Racially or religiously aggravated common assault
This offence is created by section 29(1)(c) of the Crime and Disorder Act 1998. Racially or religiously aggravated assault occasioning actual bodily harm
This offence is created by section 29(1)(b) of the Crime and Disorder Act 1998. Assault with intent to resist arrest
The offence of assault with intent to resist arrest is created by section 38 of the Offences against the Person Act 1861. Assaulting a constable in the execution of his duty
Section 89(1) of the Police Act 1996 provides that it is an offence for a person to assault either:
a constable acting in the execution of his duty; or
a person assisting a constable in the execution of his duty.Assaulting a traffic officer
This offence is created by section/10 section 10(1) of the Traffic Management Act 2004. Assaulting a person designated or accredited under sections 38 or 39 or 41 or 41A of the Police Reform Act 2002
This offence is created by section/46 section 46(1)] of the Police Reform Act 2002.