Charmaine and Maurits

Pheromones draw pairs of same species together

Mice pheromones attract male and female with different MHC

‘Major Histocompatibility Complex’Plays important role in immune system and

autoimmunityBeneficial: produce offspring with strong

immune system

Swiss zoologist Claus Wedekind set up first experiment

Recruited volunteers: 49 college women, 44 college men

Wide range of MHC genesConducted at Bern University, Switzerland

Asked men to wear a clean t-shirt for 2 days straight

Odourless soap and aftershaveAsked to remain odour neutralSweaty t-shirt returned after two daysPut into smell box with holes, one clean t-

shirt as control Women asked to sniff boxes, rated them

Women were more attracted to men with different MHC

Because women want to have varying MHC’s so that their offspring will have a wide range of MHC characteristics.