... and motherly, and taller women more assertive and intelligent? This is apparently how people perceive them in controlled studies.

So I wondered if there was any known neuroscience or biochemistry behind it - whether shorter women have a typically higher concentration of nurturing hormones (oestrogen etc) and taller ones have less, or differences in brain structure that would make them less maternal and more assertive.

Or is it just simply people's irrational prejudice?

[I know that lesbians tend to have more testosterone than straight women, and score higher in "male-typical" sections of IQ tests than straights, so women are not all created equal.]
Sure: http://www.independent.co.uk/news/uk/this-britain/why-are-tall-women-considered-superior-to-shorter-women-6153620.html