A study by an anthropologist at Indiana University Bloomington has revealed that Neanderthals and humans were more alike than previously thought. The idea of a difference in brain power was previously attributed to the dominance of early modern humans 40,000 years ago. The researchers compared MRI datasets of the brains of 100 ethnic Han Chinese and 100 Americans with European ancestry to find a large degree of overlap in brain anatomy. They also found that even small differences in behavior and brain size can potentially have significant evolutionary consequences. However, they do not believe that Neanderthal brains died out due to lack of intelligence to adapt. The study suggests that demography and genetic swamping, possibly due to cultural differences, may not have contributed to their demise.