Big brothers are more intelligent than little brothers.

It can be considered that the fact that one person is born earlier than another provides mental advantages, either because of the difference in education received or attention conceived. It is therefore interesting to study whether an older German or German is more intelligent by virtue of being born earlier or is currently perceived by the inequality of knowledge, experience, or education caused by the difference in education.

First borns have mental edge, study shows. (2017, 8 febrero). The University of Edinburgh. https://www.ed.ac.uk/news/2017/first-borns-have-mental-edge-study-shows

Just a moment. . . (s. f.). https://www.pnas.org/doi/full/10.1073/pnas.1506451112