- ^ Flynn, J. R. (1984). The mean IQ of Americans: Massive gains 1932 to 1978. Psychological Bulletin, 95, 29-51.
- ^ Flynn, J. R. (1987). Massive IQ gains in 14 nations: What IQ tests really measure. Psychological Bulletin, 101, 171-191.
- ^ "Changes in vault dimensions must occur by early childhood because of the early development of the vault." Secular change in craniofacial morphology "During the 125 years under consideration, cranial vaults have become markedly higher, somewhat narrower, with narrower faces. The changes in cranial morphology are probably in large part due to changes in growth at the cranial base due to improved environmental conditions. The changes are likely a combination of phenotypic plasticity and genetic changes over this period." Cranial change in Americans: 1850-1975.
- ^ 4.0 4.1 Rising Scores on Intelligence Test Neisser, U. (1997). American Scientist, 85, 440-447.
- ^ Mingroni, M.A. (2004). "The secular rise in IQ: Giving heterosis a closer look". Intelligence 32: 65–83.
- ^ (Ulric Neisser et al 1998)