Journal Article PHYSICAL AND PSYCHOLOGICAL VARIATION AND THE SEX RATIO Get access MARIANNE E. BERNSTEIN, MARIANNE E. BERNSTEIN Search for other works by this author on: Oxford Academic PubMed Google Scholar MILCIADES MARTINEZ-GUSTIN MILCIADES MARTINEZ-GUSTIN *6 Fair Oaks Terrace, Lexington, Massachusetts, and Bogota, Colombia, respectively. Search for other works by this author on: Oxford Academic PubMed Google Scholar Journal of Heredity, Volume 52, Issue 3, May-June 1961, Pages 109–112, https://doi.org/10.1093/oxfordjournals.jhered.a107034 Published: 01 May 1961