Few universities (I only ever came across stats for Duke and Minnesota) publish stats (though plenty give a vague idea of averages on their web pages). I can't find the Minnesota stats page, but here are the links for Duke:
http://gradschool.duke.edu/about/statistics/admitcanth.htm
http://gradschool.duke.edu/about/statistics/admitbaa.htm
As you can see from looking at past years, the stats of admitted students are quite variable. Cultural anth average GRE's have been as low as 1150 and as high as 1400...GPA's seem to be a bit more consistent, hovering around 3.5/3.6
Biological anth has slightly higher numbers most years with min/max GRE's of 1240/1425 and GPA's generally in the 3.6/3.7 range.
...so saying top programs have averages of 3.8 and 1400 may be stretching it a bit, but it's not implausible.