It is also possible that a lack of statistical power led to the lack of statistical significance in moderation. However, our results indicated that there was little overall moderation in P300 amplitude across the range of AAU. Improved sample size would not be expected to introduce practically meaningful moderation, particularly not in the genetic contribution to P300 amplitude. Perhaps increased power would have revealed that the decline in the E parameter reflects a true phenomenon. To our knowledge, no study has been conducted to support or refute this effect. Furthermore, this study examined P300 amplitude and AAU cross-sectionally. Examining the covariation of these traits longitudinally is required to identify subtle AAU effects specific to neurodevelopmental trajectories. Although we did not investigate gender differences in this report, in preliminary analyses we examined potential gender differences in how AAU might alter P300 amplitude, but moderation was not indicated for either gender. Future research with larger samples of both genders might discover the presence of gender differences in how AAU relates to P300 amplitude.
