Although this is also a smaller study (19 women and 16 men), it demonstrates excellent results. For symmetry measurements, participants measured seven bilateral traits multiple times, so errors would be minimal. Black and white photos were then taken. On the other hand, odor was measured when subjects wore the same unscented t-shirt for three consecutive nights. They then had to evaluate their honesty for any violations of the rules. Most participants did not appear to have any problems. While wearing the T-shirts, participants were not allowed to wear or shower with anything that smelled. They were also not allowed to have sexual intercourse, eat smelly foods, or smoke because this would cause a third variable (Rikowski & Grammer,