Opportunity is not a lengthy visitor.

Into the Woods (Stephen Sondheim, James Lapine)

When producers from BBC Science contacted me late in 2004 to serve as a research consultant for their TV documentary, Secrets of the Sexes, I sensed at once a great research opportunity. As part of the documentary project, BBC Science staff wanted to create an Internet Survey on psychological sex differences to be completed by thousands of people across the world, and, with the help of a number of distinguished researchers in the United Kingdom and North America, they quickly designed and implemented their proposed survey.

The results exceeded all expectations. The final version of the survey assessed participants’ sex-linked cognitive abilities, personality traits, interests, sexual attitudes and behavior, and physical traits. Almost half a million people responded at least to some parts of the survey, and over 200,000 people responded to all six parts of the survey. The resulting data set provided a unique opportunity for researchers to study sex differences in a large and diverse international sample. After preliminary analyses confirmed the richness of the BBC data, I contacted the Editor about the possibility of devoting a special section of the Archives of Sexual Behavior to papers based on the BBC data, and the papers that follow are the result of the Editor's encouraging response.

The articles in this special section address a range of “hot” topics in the study of sex differences and sexuality: sex differences and age variations in cognitive abilities, physical markers of prenatal hormones, sex differences and cultural variations in mate preferences, the relation between sex drive and attractions to men and women, and associations among birth order, handedness, and sexual orientation. All manuscripts were peer-reviewed. In addition, the Editor read and reviewed all manuscripts, and I read and reviewed all manuscripts other than my own. Special thanks go to the following Editorial Board members for their insightful reviews: Gerianne M. Alexander, J. Michael Bailey, Ray Blanchard, Meredith L. Chivers, Brian A. Gladue, Melissa Hines, and Martin L. Lalumière.

The articles that follow only scratch the surface of the many possible analyses that can be conducted on the BBC data. Nonetheless, they should whet the reader's appetite for additional research reports that will undoubtedly follow.