Twenty eight adult males participated in the study. Fourteen were
aged between 20 and 31 years (mean = 24.4 years (yr) (standard
deviation (SD) = 3.5 yr)), and made up the group of ‘younger’ adults.
The ‘older’ group consisted of 14 participants aged 43–54 years
(mean = 47.2 yr (SD = 3.4 yr)).