Are only infants held more often on the left? If so, why? Testing the attention-emotion hypothesis with an infant, a vase, and two chimeric tests, one “emotional,” one not

Abstract

Most adults, especially women, hold infants and dolls but not books or packages on the left side. One reason may be that attention is more often leftward in response to infants, unlike emotionally neutral objects like books and packages. Women's stronger bias may reflect greater responsiveness to infants. Previously, we tested the attention hypothesis by comparing women's side-of-hold of a doll, book, and package with direction-of-attention on the Chimeric Faces Test (CFT) [Harris, L. J., Cárdenas, R. A., Spradlin, Jr., M. P., & Almerigi, J. B. (2010). Why are infants held on the left? A test of the attention hypothesis with a doll, a book, and a bag. Laterality: Asymmetries of Body, Brain and Cognition, 15(5), 548-571. doi:10.1080/13576500903064018]. Only the doll was held more often to the left, and only for the doll were side-of-hold and CFT scores related, with left-holders showing a stronger left-attention bias than right-holders. In the current study, we tested men and women with a doll and the CFT along with a vase as a neutral object and a "non-emotional" chimeric test. Again, only the doll was held more often to the left, but now, although both chimeric tests showed left-attention biases, scores were unrelated to side-of-hold. Nor were there sex differences. The results support left-hold selectivity but not the attention hypothesis, with or without the element of emotion. They also raise questions about the contribution of sex-of-holder. We conclude with suggestions for addressing these issues.

The left-cradling bias and its relationship with empathy and depression

“…As highlighted in the introduction, the hypothesised effect of hemispheric asymmetries in emotional processing on the emergence of the left-cradling bias might be driven not only by the visual system but also by other sensory systems, and this could justify – at least in part – our decision to conflate shoulder and arm holding. However, we also point out how, since the beginning of cradling studies 1 , possible differences in the type of hold have been often neglected, probably because types of hold different from arm holding are rather uncommon 28,74,75 (but see also ref. 40 ).…”

Keep a Left Profile, Baby! The Left-Cradling Bias Is Associated with a Preference for Left-Facing Profiles of Human Babies

“…In this regard, it should be noticed that this hemispheric asymmetry seems to be stronger for faces expressing negative emotions such as anger, fear and sadness [16] and for faces of crying infants [17]. Using mostly the Chimeric Faces Task [18], several studies confirmed the relationship between the LCB and the right hemisphere dominance for processing emotional characteristics from faces [19][20][21][22][23] (albeit some research has yielded inconsistent results [24,25]). Moreover, Huggenberger et al [26] found that, compared with nulliparous non-left-cradling women, left-cradling ones exhibited a lower response bias to erroneously judge neutral baby faces presented in the left visual hemifield as emotional (and vice versa for stimuli presented in the right visual hemifield), concluding that women's cradling side preferences might have evolved for saving cognitive resources when monitoring emotional signals from baby faces.…”

The Role of Ethnic Prejudice in the Modulation of Cradling Lateralization

“…Moreover, it should be noticed that some researchers distinguish between different types of infant holding, for example, by contrasting proper cradling (sometimes indicated as arm-holding, in which the infant is horizontally held supine in one’s own arms) with upright holding (sometimes indicated as shoulder-holding, in which the infant is vertically held against one’s own shoulder or trunk; Harris et al 2019 ; Todd and Banerjee 2016 ; Todd and Butterworth 1998 ; Vauclair and Donnot 2005 ). Nonetheless, in the present paper we established to use the term cradling in its wider sense (without distinguishing between the different types of hold; e.g., horizontal and vertical holding), also because of the specific task involved (participants were asked to take in their arms and soothe a doll) and because we were interested only in the side, not in the final type of posture assumed.…”

“…In line with research indicating reduced empathic reactions toward individuals belonging to a prejudiced racial outgroup (e.g., Forgiarini et al 2011 ), it is plausible to hypothesize that a situation in which the cradling individual has a prejudice toward the cradled individual is comparable to a situation in which the cradling individual has a general lack of empathy (Fleva and Khan 2015 ; Malatesta et al 2019b ; Pileggi et al 2015 ). However, given that a significant left-cradling bias comparable to that of females has been found in males (e.g., Harris et al 2019 ), but to a lesser extent (with some exceptions for new fathers; Dagenbach et al 1988 ; Harris et al 2007 ; Scola and Vauclair 2010 ), any factor modulating such a side preference should be more likely to emerge in women. Therefore, in this study, we examined whether women with high levels of prejudice toward a specific ethnic group would show reduced left-cradling preferences when asked to take in their arms and soothe an infant-like doll with ethnic features of the prejudiced group compared to women with low levels of prejudice and/or those asked to cradle an infant-like doll with ethnic features of their own group.…”

“…However, in light of the conspicuous literature on human cradling, reducing the complexity of this lateralized behavior to a mere issue of motor or perceptual asymmetries seems to be simplistic. For example, the role of hemispheric specialization for face processing in modulating the laterality of cradling in women has not always been confirmed (e.g., Donnot and Vauclair 2007 ; Harris et al 2019 ; Lucas et al 1993 ), and even when it has, the effect size observed is rather small, suggesting that other factors are involved. Moreover, much cradling research has focused on the emotional state of the cradler.…”