On the other hand, it may be possible to be too attractive. Segal & Ostrove (1975) found that females who were guilty of crimes related to their attractiveness got larger sentences, and Dermer & Thiel (1975) found that attractive women are judged as being egotistic and materialistic. This can be interpreted as the opposite of the halo effect.
Research such as the above has received criticism for relying in asking people to rate pictures of people to measure their attractiveness. This is very subjective and can vary immensely from individual to individual and from culture to culture, so it is cannot be taken as a reliable measure of attractiveness.
Similarly, the studies attempted to rate attractiveness on a scale from “attractive” to “unattractive” with the assumption that everybody would find the “attractive” people attractive and vice versa for those who were “unattractive”. It may be, however, that people are attracted to people on the same “level” as themselves in terms of attractiveness.
Walster et al. (1966) proposed a “matching hypothesis” which describes this idea. In their study, college students were assigned dates at random for a dance, but were told that the assignment of partners was based on a questionnaire that they had filled in to find their perfect match. When asked if they liked their date, physical attractiveness was found to be the biggest factor in producing an affirmative response, irrespective of the person’s own attractiveness. Although this does not support the matching hypothesis, it was criticised for its lack of relevance to real life, as people are often not assigned dates and can choose them for themselves. In 1969, Walster and Walster conducted a similar study, but allowed the students to meet each other first and were allowed to choose who they would prefer to go with. It was found that students chose dates that had a comparable level of attractiveness to themselves. This does not necessarily imply attraction, however; instead it may have been fear of rejection that caused people to select others on a similar level to themselves. Further support for the matching hypothesis comes from Murstein (1972), who presented pictures of 'steady or engaged' couples, and 'random' couples who were only together for the purposes of the photograph. The steady and engaged couples were consistently rated as being of similar attractiveness, more so than the random couples.
Much research into physical attraction can be criticised for focusing on short-term, dyadic meetings between people. It is also reductionist because it focuses only on the physical elements of attraction and does not take into account other factors such as personality traits. Some of the research is also deterministic, implying that one's future is significantly affected by their physical attractiveness. Emphasis on this in studies may itself raise ethical issues, in that it can be interpreted by many to be offensive.
Evolutionary theory offers another explanation for interpersonal attraction. This theory explains attraction in terms of fertility, health and reproduction, indicating that men look for youthful and fertile looks in women and women look for men who can protect them and their children. Singh (1993) identified one factor that may influence a man's perception of a woman: her waist-to-hip ratio (WHR). When girls go through puberty, their body shape changes such that fat is deposited in their lower body, making the size of the hips larger than that of the waist. Singh identified the optimum WHR as being 0.7, which he also noted as indicating health and fertility. Singh's 0.7 WHR theory has been tested in different countries and found still to hold, so it has cultural validity, but it may not be ecologically valid as the experiments relied on line-drawings as opposed to real photographs or seeing people 'in the flesh'. Nonetheless, the findings still held when Henss (2000) used photographs which were edited using computer software to indicate different ratios, supporting further the theory. Evolutionary theory suggests that women look for men who, again, are healthy and fertile, but who are also strong and can protect them and their children. Herzog & Franzoi (1987) in a study of American college students found that the most attractive quality in men is the upper body. Other studies have found broad shoulders and an 'upside-down triangle' shape is the most attractive: broad shoulders and a smaller waist.