• The effects of sex and handedness on masturbation laterality and other lateralised motor behaviours

      Rodway, Paul; Thoma, Volker; Schepman, Astrid; University of Chester; University of East London (Taylor and Francis, 2021-11-26)
      Masturbation is a common human behaviour. Compared to other unimanual behaviours it has unique properties, including increased sexual and emotional arousal, and privacy. Self-reported hand preference for masturbation was examined in 104 left-handed and 103 right-handed women, and 100 left-handed and 99 right-handed men. Handedness (modified Edinburgh Handedness Inventory, EHI), footedness, eyedness, and cheek kissing preferences were also measured. Seventy nine percent used their dominant hand (always/usually) for masturbation, but left-handers (71.5%) were less consistently lateralised to use their dominant hand than right-handers (86.5%). Hand preference for masturbation correlated more strongly with handedness (EHI), than with footedness, eyedness, or cheek preference. There was no difference in masturbation frequency between left and right-handers, but men masturbated more frequently than women, and more women (75%) than men (33%) masturbated with sex aids. For kissing the preferred cheek of an emotionally close person from the viewer’s perspective, left-handers showed a left-cheek preference, and right-handers a weaker right-cheek preference. The results suggest that hemispheric asymmetries in emotion do not influence hand preference for masturbation but may promote a leftward shift in cheek kissing. In all, masturbation is lateralised in a similar way to other manual motor behaviours in left-handed and right-handed men and women.
    • A leftward bias for the arrangement of consumer items that differ in attractiveness

      Rodway, Paul; Schepman, Astrid; University of Chester (Taylor & Francis, 2020-06-24)
      People are frequently biased to use left side information more than right side information to inform their perceptual judgements. This research examined whether the leftward bias also applied to preferences for the arrangement of everyday consumer items. Pairs of consumer items were created where one item was more attractive than the other item. Using a two-alternative forced choice task, Experiment 1 found a robust preference for arrangements with the more attractive consumer item on the left side rather than the right side of a pair. Experiment 2 reversed the judgement decision, with participants asked to choose the arrangement they least preferred, and a bias for arrangements with the more attractive item on the right side emerged. Experiment 3 failed to find an effect of the ‘attractive left’ preference on participants’ purchasing intentions. The preference for attractive left arrangements has implications for the display of consumer products and for the aesthetic arrangement of objects in general. The findings are discussed in relation to hemispheric asymmetries in processing and the role of left to right scanning.
    • Limb preference and personality in donkeys (Equus asinus)

      Diaz, Sergio; Murray, Lindsay Elaine; Rodway, Paul; University of Chester; Universidad Autónoma de Madrid (Taylor and Francis, 2021-02-05)
      Interhemispheric laterality has often been linked to different behavioural styles. This study investigates the link between limb preference and personality in donkeys. The sample consisted of 47 donkeys (Equus asinus), 30 males and 17 females. Limb preference was determined using observation of the leading limb in a motionless posture and personality was measured using the Donkey Temperament Questionnaire (French, J. M. (1993). Assessment of donkey temperament and the influence of home environment. Applied Animal Behaviour Science, 36(2), 249–257. doi:10.1016/0168-1591(93)90014-G) completed by the donkeys’ keepers. A Principal Component Analysis obtained two components: Agreeableness and Extraversion. Age showed a positive relationship with Agreeableness, echoing trends in humans Donkeys did not show a population-level preference towards either side. Limb preference significantly predicted the trait difficult to handle: donkeys with a preference to keep the right foot forward when motionless were harder to handle. This study presents the first investigation into limb preference and personality in donkeys, although more research is needed to clarify whether there is a population-level limb preference bias in donkeys, and the relationship between limb preference and Agreeableness.
    • Who goes where in couples and pairs? Effects of sex and handedness on side preferences in human dyads

      Rodway, Paul; Schepman, Astrid; University of Chester (Taylor and Francis, 2022-06-21)
      There is increasing evidence that inter-individual interaction among conspecifics can cause population-level lateralization. Male-female and mother-infant dyads of several non-human species show lateralised position preferences, but such preferences have rarely been examined in humans. We observed 430 male-female human pairs and found a significant bias for males to walk on the right side of the pair. A survey measured side preferences in 93 left-handed and 92 right-handed women, and 96 left-handed and 99 right-handed men. When walking, and when sitting on a bench, males showed a significant side preference determined by their handedness, with left-handed men preferring to be on their partner’s left side and right-handed men preferring to be on their partner’s right side. Women did not show significant side preferences. When men are with their partner they show a preference for the side that facilitates the use of their dominant hand. We discuss possible reasons for the side preference, including males preferring to occupy the optimal ‘fight ready’ side, and the influence of sex and handedness on the strength and direction of emotion lateralization.