babies; however, the researchers in this study believe this may be a reflection and compensation of the decreased attention babies with facial deformities experience. Evolutionary biology David Brin speculates that many factors, such as enlarging brain size, changing environments and selection pressures, have contributed to changes in facial structure over time. David Perrett has argued that diet has had an impact on facial features, and leading some to speculate that this trend could continue, and that in the future, humans might have further neotenized features. See also Attachment theory Neoteny in humans References Further reading Biological Altruism at the Stanford Encyclopedia of Philosophy Developmental psychology Child development Human evolution