and generalize results on the effects of genetic and environmental factors on characteristics and their evolution across time. QTL analysis study Quantitative trait locus (QTL) analysis is a statistical approach for attempting to explain the genetic basis of variation in complex characteristics by linking two types of data: phenotypic data (trait measurements) and genotypic data (typically molecular markers). Researchers in disciplines as diverse as agriculture, biology, and medicine use QTL analysis to relate complicated traits to particular chromosomal regions. The purpose of this procedure is to determine the action, interaction, quantity, and type of action. The ability to disentangle the genetic component of complex characteristics has been enabled by QTL studies in model systems. To research behavioural characteristics such as schizophrenia, bipolar disorder, alcoholism, and autism, large-scale national and international alliances have been constructed. Such partnerships will bring together enormous, consistently gathered samples, improving the likelihood of finding real susceptibility gene connections. Biometric model fitting The method is designed in collaboration of quantitative geneticists to enhance the capabilities to delineate between the genetic and environmental components of complex behavioural characteristics. Path analysis and structural equation modelling are two statistical approaches used in this methodology. The approach is used to see if genetic and environmental impacts can be employed in various populations. It would be useful to know how much of the total genetic variance—heritability—is accounted for by a limited selection of potential loci in studies of emotional stability, for example. See also Behavioral epigenetics Biocultural evolution References Further reading Carey, G. (2003) Human Genetics for the Social Sciences. Thousand Oaks, CA: Sage Publications. DeFries, J. C., McGuffin, P., McClearn, G. E., Plomin, R. (2000) Behavioral Genetics 4th ED. W H Freeman & Co. Scott, J.P. and Fuller, J.L. (1965) Genetics and the Social Behavior of the Dog. University of Chicago Press. Weiner, J. (1999) Time, Love, Memory : A Great Biologist and His Quest for the Origins of Behavior. Knopf Pinker, S. (2002) The Blank Slate: The Modern Denial of Human Nature. External links Free Massively Open Online Course on human behavior genetics by Matt McGue of the University of Minnesota Behavioural sciences Human genetics Behavioural genetics