The IQ/T-Geo-Climatic Origin (GCO) theory admits that primordial northbound migration out of Africa increasingly demanded higher IQ and decreased aggression as temperatures sank. To organisms with a fixed intra-systemic energy budget, this meant that small-brained - High T (Lo-IQ/Hi-T)" masculine aggressive A5 males became too "expensive" in cold eco-niches, and were replaced by Low Testosterone androgyne A1 (Hi-IQ/Lo-T) light-weight males with sufficient energy for developing the large energy-greedy brain needed for survival during cold winters. The physiological re-balancing of T-Nexus and IQ-Nexus traits probably occurred during migration over the past 40,000 years. The moderate heritability of the traits leads us to expect that rudiments of this evolutionary progression can still be identified in contemporary geographic race and androtype distributions of inversely related T- and IQ-Nexus traits. Rushton's three-racial ranking of Life History traits (Table 1 in Nyborg, this issue,) confirms this, as do analyses using the General Trait Covariance model on data for five races and pentile IQ bands. The evolutionary progression seems time-limited, however, as recent decennia witness a decaying Western civilization. (C) 2012 Elsevier Ltd. All rights reserved.