Based on this comic, which captures perfectly my cohort's Darwinian ethos.
Product Details:Size Chart
Male model is 5'7" and wearing a men's medium
Female model is 5'9" and wearing a women's medium
Men's printed on Port & Company, cotton-poly blend, heather charcoal t-shirt
Women's printed on American Apparel, cotton-poly blend, heather charcoal t-shirt