Age Normalized Testosterone Peaks at Series B for Male Startup Founders

TL;DR

This study reveals that male startup founders' testosterone levels peak at Series B funding, correlating with confidence and dominance, and decline afterward, reflecting stress and pressure during startup growth stages.

Contribution

It uncovers the dynamic pattern of testosterone levels across startup funding stages and supports the dual-hormone hypothesis in entrepreneurial contexts.

Findings

Testosterone increases by 55.7% from pre-seed to seed funding.

Testosterone peaks at Series B, being 99.6% higher than pre-seed.

Post-Series B, testosterone drops by 42.2%, with cortisol levels rising.

Abstract

In a study of 107 male Y Combinator founders, a surprising correlation between age-normalized testosterone and company stage was uncovered. Testosterone, a hormone associated with confidence, dominance, and drive, increased by 55.7% from pre-seed to seed funding, peaking at the Series B stage, where levels were 99.6% higher than pre-seed. After series B funding, testosterone was observed to drop by 42.2%, coinciding with a spike in cortisol levels. This age-normalized biomarker analysis supports the dual-hormone hypothesis, illustrating that early startup success fosters feelings of dominance and confidence, while later-stage pressures and stresses erode these feelings. An alternative interpretation of the data, which suggests the opportunity for a longitudinal study, is that male founders with higher testosterone are more likely to raise larger rounds of funding.