Testing Fraternal Birth Order Effects and Antagonistic Effects for Homosexual Men: Power Comparison of Various...

Area of Science:

• Behavioral Neuroscience
• Genetics
• Psychology

Background:

• The older brother effect (FBOE) and maternal antagonist effect (AE) are hypothesized biological determinants of male homosexual preference.
• Both effects can lead to homosexual men having more siblings and older siblings than heterosexual men.
• Distinguishing between FBOE and AE requires statistical methods that control for the other effect.

Purpose of the Study:

• To formally compare existing statistical approaches for discriminating between the FBOE and AE using simulated data.
• To evaluate the performance of these tests in terms of their ability to reject the null hypothesis under specified alternative hypotheses.

Main Methods:

• Utilized simulated family data to rigorously assess statistical tests.
• Compared approaches based on regression, Bayesian modeling, and contingency tables.
• Evaluated tests for their power, type-I error rates, practicability, and ability to control for confounding variables.

Main Results:

• For FBOE detection, test performance varied significantly depending on the underlying effect-generating function; no single test was universally superior.
• Some tests for FBOE consistently performed poorly or exhibited high type-I error rates.
• For AE detection, a clear ranking of test performance was established across all tested parameter values.

Conclusions:

• The choice of statistical test for investigating FBOE and AE is critical and depends on the specific hypotheses and data characteristics.
• Some commonly used statistical methods may be unreliable for distinguishing these effects.
• Further research should consider the practical limitations and statistical properties of each test when analyzing family data related to sexual orientation determinants.