largely rely upon distinctly organized social structures to combat the threat of diseases, it is evident such systems would be strained to apply in most modern human societies. the study describes "perceptual cues" that humans use that will trigger aversive behavior toward other individuals. for example, people who appear to be ill may stimulate avoidance behavior in those around them, particularly if the others around them have temporarily suppressed immune systems. wilson et al., 2003, speculated that gregarious species may invest less overall in their immune functions because so many of the body's resources must go to support somatic growth and competition among mates. one potential explanation, therefore, for human hypersensitivity to the perception of disease threat is that we are left relatively vulnerable by our under-provisioned immune systems. schaller and park (2011) also make a connection between the experience of disgust and things that do pose actual threat of pathogen risk, however this "disgust" experience has a tendency to be over-applied rather than under-applied in the favor of the individual's health and is therefore triggered by things that resemble disgust-inducing objects or actions. such research has enormous implications for the explanation of aspects ranging from cultural diet variance to conformity and xenophobia. schaller and murray (2008) ran a comparison against research by grunier et al. (2004) that displayed the variability of the prevalence of pathogens on a geographic scale. schaller and murray (2008) found overlap in cultural differences that included food preparation, mate selection and family structure, and sociosexual practices. in regions where infectious disease threat was lower, people trended toward more liberal sexual practices, more extroverted personalities, and less "self-conscious" behavior. in the 2011 article "the behavioral immune system", the authors discuss how avoidance behaviors can also be triggered when an individual witnesses another individual violating social norms, hence a general trend toward ethnocentrism and wariness of foreigners. especially during times of known pathogenic outbreak, this can be so extreme as to manifest itself in the form of xenophobia. wu and chang's 2011 study elucidated trends toward conformity that they believe may have evolved as a protective dynamic against the introduction of contagions. although research in this area is still very new, it provides a logical and cogent connection between particulars of human sociality and disease transmission. it furthermore stimulates key insight into cultural dynamics that assist in human survival.