Published online by Cambridge University Press: 17 May 2016
Although I am intrigued by the recent efforts of several researchers who have taken issue with Sulloway's (1996) work on birth order, I experience some hesitancy to comment for a number of reasons. Birth order research has historically come up with contradictory findings (Nyman, 1995). In the main, I suspect that the apparent inconsistencies will be resolved not through commentary but with keener measuring tools, better experimental controls, and with the patience and energy to define each research condition so as to enable accurate replication. It is also not an easy assignment to critique the work of scientists whom I admire, especially when their inferences seem to be at odds. With this said, I shall attempt to deal with design issues inherent in birth order research in an effort to illustrate some of the factors that enter into the contradictory findings reported in the literature.