All of the IQ juice usually gets used up on the first child

'child':13 'first':12 'get':7 'iq':4 'juic':5 'use':8 'usual':6

'child':2 'first':1 'higher':4 'varianc':5

Base rates - first borns are more numerous

'base':1 'born':4 'first':3 'numer':7 'rate':2

Firstborns with siblings think they're smarter than average, because their main childhood experience is interacting with younger siblings who don't know as much.

'averag':9 'childhood':13 'experi':14 'firstborn':1 'interact':16 'know':23 'main':12 'much':25 're':6 'sibl':3,19 'smarter':7 'think':4 'younger':18

This whole market will resolve NA in a week or two if/when there isn't much discussion