Differences between left- and right-handers in approach/avoidance motivation: influence of consistency of handedness measures

Hand preference is often viewed as a troublesome variable in psychological research, with left-handers routinely excluded from studies. Contrary to this, a body of evidence has shown hand preference to be a useful variable when examining human behavior. A recent review argues that the most effective way of using handedness as a variable, is a comparison between individuals who use their dominant hand for virtually all manual activities (consistent handers) versus those who use their other hand for at least one activity (inconsistent handers). The authors contend that researchers should only focus on degree of handedness rather than direction of preference (left versus right). However, we argue that the field suffers from a number of methodological and empirical issues. These include a lack of consensus in choice of cut-off point to divide consistent and inconsistent categories and importantly a paucity of data from left-handers. Consequentially, researchers predominantly compare inconsistent versus consistent right-handers, largely linked to memory, cognition and language. Other research on response style and personality measures shows robust direction of handedness effects. The present study examines both strength and direction of handedness on self-reported behavioral inhibition system (BIS) and behavioral activation system (BAS) scores, using evidence from a large (N = 689) dataset including more than 200 left-handers. There were degree of handedness effects on BIS and BAS-Fun Seeking, but effects are largely driven by differences between consistent left-handers and other groups. Choice of cut-off point substantively influenced results, and suggests that unless a suitable sample of left-handers is included, researchers clarify that their degree of handedness effects are applicable only to right-handers. We concur that strength of hand preference is an important variable but caution that differences related to consistency may not be identical in right and left-handers

Are left-handers really more anxious?

Research examining anxiety and handedness is inconclusive. Davidson and Schaffer (1983) found left-handers had higher trait anxiety, while Beaton and Moseley (1991) found no state or trait differences. Such studies potentially have methodological issues, and we have argued that handedness related reactivity differences (Wright & Hardie, 2011) suggest that state anxiety needs to be measured within a context. Thus the current study investigated state and trait anxiety levels in an experimental situation. We found left-handers had significantly higher state scores, supporting the right hemisphere's role in negative affect and inhibition. It also fits with predictions based on the behavioural inhibition system's role in the revised reinforcement sensitivity theory (rRST). No trait differences were found, but there was a significant relationship between trait and state anxiety. Using ANCOVA to control for the influence of trait anxiety on state anxiety, we still found a handedness effect. When participant's trait anxiety levels were similar, left-handers showed a relatively larger state response. We conclude that in the context of an experiment, state anxiety was directly correlated with trait anxiety but that the relatively higher reactivity of left-handers may be a major influence on how they respond in a new situation

The relationship between Revised Reinforcement Sensitivity Theory (rRST), handedness and indecision

Indecisiveness is an inability to make a decision, manifest across a number of behaviours. We explore the influence that both direction and strength of hand preference may have on this construct, examining it in relation to the revised Reinforcement Sensitivity Theory (rRST). Frost and Shows’ (1993) Indecisiveness Scale was administered to 328 undergraduates (221 females), alongside the Edinburgh Handedness Inventory (Oldfield, 1971) and Carver and White’s (1994) BIS/BAS scales. Simple correlations showed left-handers had a positive relationship between strength of handedness and BIS. In right-handers, strength and aversive indecision were positively correlated. Regression analysis demonstrated no significant relationship between hand strength and indecision, but that indecision was related to all three measures of rRST. Consistent with previous work, BIS was positively related to all indecision but particularly aversive, while BAS was negatively related to indecision but most strongly the avoidant category. We found that FFFS is more closely related to aversive than avoidant indecision. The relationship between rRST and indecision may be influenced by handedness; for right-handers the same pattern was found, but in left-handers BAS was not a significant predictor of indecision, BIS only predicted aversive indecision and FFFS predicted all three categories

Influences of lateral preference and personality on behaviour towards a manual sorting task

Differences in task behaviour between left- and right-handers and left- and right-eared individuals have been reported (e.g. Jackson, 2008 and Wright et al., 2004) with left-handers taking longer to begin a task and right-eared individuals having a more disinhibited approach. Personality measurements are also important when examining approach behaviour. Jackson (2008) reported that those with higher neuroticism levels and a right-ear preference react faster to tasks. The current study investigated the effects of lateral preference and personality on behaviour towards a manual sorting task. Eighty-five participants completed laterality and personality scales and a card-sorting task. Degree of hand preference was found to influence behaviour towards the task with strong left-handers taking longer to begin. Those with a left congruent lateral preference (left-hand, left-ear) took significantly longer to begin the task than those with a right congruent preference. Neither neuroticism nor extraversion influenced task approach. We concluded that hand preference, and more specifically a strong left-hand preference is a good predictor of a longer initiation time on a manual task. Ear preference on its own does not predict initiation time

Handedness and behavioural inhibition:left-handed females show most inhibition as measured by BIS/BAS self-report

This study investigated the relationship between handedness, gender and behavioural approach and inhibition using Carver and White’s (1994) BIS/BAS Scale. 112 participants took part: 46 left-handers and 66 right-handers. All participants completed Peters’ (1998) handedness questionnaire followed by the self-report BIS/BAS Scale. Significant effects of both handedness and gender on the BIS scores were found, with left-handers and females scoring significantly higher on inhibition. BIS scores were re-examined to include FFFS scores, which showed a significant effect of gender. Revised BIS scores replicated the original BIS findings. These findings are discussed in relation to handedness research

Handedness and social anxiety:using Bryden's research as a catalyst to explore the influence of familial sinistrality and degree of handedness

Phil Bryden's work has impacted on many areas of laterality, including degree and measurement of hand preference, as well as influences of familial sinistrality (FS). For example, Bryden[(1977). Measuring handedness with questionnaires. Neuropsychologia, 15, 617–624] is a well-cited and influential paper that remains relevant to this day. Inspired by this we extended our analysis of the relationship between handedness and anxiety in a number of ways. We used familial handedness and strength of handedness to examine their potential influences on anxiety, and extended our research by exploring their relationship to social anxiety, using the Social Phobia Inventory (SPIN). Inconsistent left-handers (ILH) were found to be more socially anxious. In all categories of SPIN except avoidance, ILH were significantly more anxious than consistent right- and left-handers. There were FS differences between ILH with a first degree left-handed relative (FS+) compared to ILH with no first degree left-handed relative (FS−) on all categories of anxiety scores. Within FS+ participants, ILH had significantly higher anxiety scores, compared with consistent handers across all categories. This suggests that ILH's social anxiety may be influenced by a close left-handed relative. Inspired by examining Bryden's work for this special issue, we will continue to add both strength of preference and familial handedness to our work

The behaviour of mixed-species tamarin groups (Saguinus labiatus & Saguinus fuscicollis)

Saguinus labiatus lahiatus and S. juscicollis weddelli form stable mixed-species groups in the wild. This thesis investigates the costs and benefits of such an association, with particular emphasis on determining species differences, the "behavioural differences hypothesis". A nine month field study was conducted in northern Bolivia, which showed that the species differed in mean height used in the forest, method of locomotion, and preferred insect foraging strategies. Subsequent investigations were conducted on captive single species and mixed-species groups at Belfast Zoo. Preliminary observations of mixed-species groups in standard enclosures and while free-ranging, demonstrated that they behaved in a similar way to their wild counterparts, where the S. labiatus had priority of access to food and utilised a higher mean height in the cage. Therefore, it is reasonable to relate the results of captive investigations to the wild situation. The "behavioural differences hypothesis" was investigated through the presentation of novel objects in various parts of the environment. Both species' reactions to objects varied according to predictions based on their vertical partitioning. S. labiatus were found to use a more visually orientated approach than S. juscicollis, and this can be related to insect foraging strategies in the wild. An experiment was conducted with novel food and non-food objects, in order to test the "social facilitation hypothesis", which predicts that the behaviour of one species can orientate the other towards the presence of food. Results suggest that S. labiatus have priority of access to objects and are first to consume food, but S.juscicollis are able to use this behaviour and always gained some food. The results suggest that overall both species benefit from increased foraging efficiency. The hypothesis that individuals in mixed-species groups benefit from decreased predation through increased vigilance was investigated, and supported, as members of both species were shown to benefit from a decrease in individual vigilance effort, but an overall increase in total vigilance per unit time. This was shown in both general vigilance and in the active monitoring of a threatening stimuli. Findings are discussed in terms of costs and benefits towards the participants in mixedspecies groups, and are compared to the main theoretical viewpoints in th

The Individual Recovery Outcomes Counter:preliminary validation of a personal recovery measure

Aims and methodThe Individual Recovery Outcomes Counter (I.ROC) is to date the only recovery outcomes instrument developed in Scotland. This paper describes the steps taken to initially assess its validity and reliability, including factorial analysis, internal consistency and a correlation benchmarking analysis.ResultsThe I.ROC tool showed high internal consistency. Exploratory factor analysis indicated a two-factor structure comprising intrapersonal recovery (factor 1) and interpersonal recovery (factor 2), explaining between them over 50% of the variance in I.ROC scores. There were no redundant items and all loaded on at least one of the factors. The I.ROC significantly correlated with widely used existing instruments assessing both personal recovery and clinical outcomes.Clinical implicationsI.ROC is a valid and reliable measure of recovery in mental health, preferred by service users when compared with well-established instruments. It could be used in clinical settings to map individual recovery, providing feedback for service users and helping to assess service outcomes.</p

Factor validation and Rasch analysis of the individual recovery outcomes counter

Objective: The Individual Recovery Outcomes Counter is a 12-item personal recovery self assessment tool for adults with mental health problems. Although widely used across Scotland, limited research into its psychometric properties has been conducted. We tested its' measurement properties to ascertain the suitability of the tool for continued use in its present form.Materials and methods: Anonymised data from the assessments of 1,743 adults using mental health services in Scotland were subject to tests based on principles of Rasch measurement theory, principal components analysis and confirmatory factor analysis.Results: Rasch analysis revealed that the 6-point response structure of the Individual Recovery Outcomes Counter was problematic. Re-scoring on a 4-point scale revealed well ordered items that measure a single, recovery-related construct, and has acceptable fit statistics. Confirmatory factor analysis supported this. Scale items covered around 75% of the recovery continuum; those individuals least far along the continuum were least well addressed.Conclusions: A modified tool worked well for many, but not all, service users. The study suggests specific developments are required if the Individual Recovery Outcomes Counter is to maximise its' utility for service users and provide meaningful data for service providers.*Implications for Rehabilitation*Agencies and services working with people with mental health problems aim to help them with their recovery.*The individual recovery outcomes counter has been developed and is used widely in Scotland to help service users track their progress to recovery.*Using a large sample of routinely collected data we have demonstrated that a number of modifications are needed if the tool is to adequately measure recovery.*This will involve consideration of the scoring system, item content and inclusion, and theoretical basis of the tool

The enigma of facial asymmetry:is there a gender specific pattern of facedness?

Although facial symmetry correlates with facial attractiveness, human faces are often far from symmetrical with one side frequently being larger than the other (Kowner, 1998). Smith (2000) reported that male and female faces were asymmetrical in opposite directions, with males having a larger area on the left side compared to the right side, and females having a larger right side compared to the left side. The present study attempted to replicate and extend this finding. Two databases of facial images from Stirling and St Andrews Universities, consisting of 180 and 122 faces respectively, and a third set of 62 faces collected at Abertay University, were used to examine Smith's findings. Smith's unique method of calculating the size of each hemiface was applied to each set. For the Stirling and St Andrews sets a computer program did this automatically and for the Abertay set it was done manually. No significant overall effect of gender on facial area asymmetry was found. However, the St Andrews sample demonstrated a similar effect to that found by Smith, with females having a significantly larger mean area of right hemiface and males having a larger left hemiface. In addition, for the Abertay faces handedness had a significant effect on facial asymmetry with right-handers having a larger left side of the face. These findings give limited support for Smith's results but also suggest that finding such an asymmetry may depend on some as yet unidentified factors inherent in some methods of image collection