Katzmarzyk and Leonard similarly note in 1998 that human populations appear to follow the predictions of Allen's rule. They said that there is a negative association between body mass index and mean annual temperature for indigenous human populations, meaning that people who originate from colder regions have a heavier build for their height and people who originate from hotter regions have a lighter build for their height. They said that relative sitting height is negatively correlated with temperature for indigenous human populations, meaning that people who originate from colder regions have proportionately shorter legs for their height and people who originate from hotter regions have proportionately longer legs for their height.[7]