Interhemispheric interaction and beliefs on our origin: Degree of handedness predicts beliefs in creationism versus evolution

Abstract

It has been suggested that strongly handed individuals have attenuated systems for updating beliefs compared to mixed handers (Niebauer, Aselage, & Schutte, 2002). The current research extended this theory to individual differences in updating beliefs concerning our origins. Although the theory of evolution has gained overwhelming success in the sciences, a significant percentage of the population believes in biblical creationist accounts of human origins that are inconsistent with accepted, contemporary scientific views. If strongly handed individuals possess attenuated systems for updating beliefs, they might be more likely to believe in creationism. In two studies, strongly handed participants were more likely to believe in creationism while mixed-handed participants were more likely to believe in evolution. A model of how interhemispheric interaction functions in maintaining and updating beliefs is discussed. Specifically, mixed-handedness seems to be associated with a lower threshold for updating beliefs.

A neuropsychological dimension for anchoring effects

“…In summary, a similar pattern of changes in mental representations as a function in handedness was found in all three studies: mixed-handers were (i) more likely to revise their risk estimates when provided with factual information (Jasper et al, 2002), (ii) more likely to progress from creationist to evolutionary beliefs given further biological education (Niebauer, Christman, Reid, & Garvey, 2004), and (iii) more open to persuasive arguments than strong right-handers . Comparable findings reviewed earlier include those of Niebauer et al (2002), where people came into the lab believing that the fake arm was not theirs, but, given appropriate visual and tactile information, mixed-handers were more likely to change beliefs and assume ownership of the fake arm.…”

Degree versus direction: A comparison of four handedness classification schemes through the investigation of lateralised semantic priming

“…Christman's method, which is based on exploratory analyses of data collected over several years, utilises a median split of the sample in order to classify participants such that those with a score of '80 or more on the EHI (Oldfield, 1971) are classed as SHs whereas a score of '75 or below is obtained by MHs. A strength of this classification system is that evidence from behavioural (Niebauer, 2004;Niebauer et al, 2004;Ponton, 1987;Propper, Lawton, Przyborski, & Christman, 2004;Weinrich, Wells, & McManus, 1982), genetic (Annett, 2002;Collins, 1991;McManus, 1985), evolutionary (Corballis, 1997;Coren & Porac, 1977;Harris, 2000), and physiological studies (Beaton, 1997;Clarke & Zaidel, 1994;Denenberg, Kertesz, & Cowell, 1991;Habib et al, 1991;Witelson & Goldsmith, 1991) all bolster the notion that degree of handedness may be more important than direction of handedness (Christman, 2009). However, this methodology does not acknowledge that there may be differences within the MHs that may be important for exploring functional lateralisation. That is, there is a much greater range of scores possible on the EHI by those who are classified as MHs ((100 to '75) compared to those classified as SHs, whose scores range by only 20 points ('80 to '100).…”

“…The term ''ambidextrous'' has also been used to classify those who use the right hand for some activities and the left hand for others, although it has been argued that true ambidexterity (i.e., being able to do the same activity equally well with both hands), is quite rare (Moynihan & Breathnach, 1995). Christman and colleagues (Christman, 1995;Christman, Propper & Brown, 2006;Niebauer, Christman, Reid, & Garvey, 2004) have argued for a different classification system, stating that it is the degree of handedness and not the direction that matters most. According to this system, people can be classified into one of two groups: those who use one hand for nearly all activities (i.e., stronghanders; SHs) and those who use their non-dominant hand for some activities (i.e., mixed-handers; MHs).…”

“…This finding is in accordance with the literature (Knecht et al, 2000;Kirveskari et al, 2006;Szaflarski et al, 2002) in that stronger left-handedness is associated with increased right hemisphere language lateralisation. The third classification system used the basic principle of the model proposed by Christman and colleagues (Christman, 1995;Christman et al, 2006;Niebauer et al, 2004) of grouping participants as either mixed-handed or strongly handed. According to this system, SHs are those who use a single hand (the right hand) for nearly all tasks, while MHs are those who complete at least one activity with their non-dominant hand.…”

Laterality of voluntary motor tasks: Are basketing, targeting, and peg-moving performance asymmetric?

“…A number of studies have recently been carried out in animals as it was in humans; paw preferences (Tan et al, 1991;Tan, 1993b;Yetkin, 2001) and physical properties in cats are closely related to the measurements of hand and foot sizes in human. There is a harmonic relation between the use of the hand and brain functions as evolutionary phenomena (Niebauer et al, 2004). In the anthropologic process, the brain develops a device and the hand is used to make it.…”