Abstract and Introduction
It has been suggested that the degree of compassion—the feeling of warmth, understanding and kindness that motivates the desire to help others, is modulated by observers' views regarding the target's vulnerability and suffering. This study tested the hypothesis that as compassion developed to protect vulnerable kinships, hormones such as oxytocin, which have been suggested as playing a key role in 'tend-and-befriend' behaviors among women, will enhance compassion toward women but not toward men. Thirty subjects participated in a double-blind, placebo-controlled, within-subject study. Following administration of oxytocin/placebo, participants listened to recordings of different female/male protagonists describing distressful emotional conflicts and were then asked to provide compassionate advice to the protagonist. The participants' responses were coded according to various components of compassion by two clinical psychologists who were blind to the treatment. The results showed that in women and men participants oxytocin enhanced compassion toward women, but did not affect compassion toward men. These findings indicate that the oxytocinergic system differentially mediates compassion toward women and toward men, emphasizing an evolutionary perspective that views compassion as a caregiving behavior designed to help vulnerable individuals.
Human pro-social behaviors are characterized by acts undertaken to protect or promote the welfare and safety of other persons or groups (Schwartz and Bilsky, 1990). These behaviors, which integrate individuals into a cohesive and united society, have social evolutionary value as through such behaviors humans provide physical and mental levels of security to each other, well beyond what individuals could possibly achieve alone (Darwin, 1871/2004; De Dreu, 2012). One of the salient pro-social feelings that drive us to help others is compassion. Compassion may be defined as the feeling of warmth, understanding, sadness and kindness that arises in witnessing the distress and suffering of others. This feeling motivates the desire to help and care for others (Lazarus, 1991; Goetz et al., 2010). Compassion is a complex and multidimensional feeling that integrates not only the sense of empathy—the ability to recognize, understand and metalize the thoughts, desires and feelings of others (Davis, 1996; Batson, 2009)—but also the ability to recognize that someone else suffers and to separate the distress of the other from self-distress (Lazarus, 1991; Nussbaum, 1996). Furthermore, compassion motivates caring behaviors aimed at relieving the suffering and distress of others (Batson, 1998; Goetz et al., 2010). Thus, compassion is a complex emotional state that motivates pro-social behavior. Zaki and Ochsner (2012) recently proposed, a model of empathy, which includes three components: (i) affective empathy and experience sharing, (ii) cognitive empathy and mentalization ability, (iii) empathic motivation and empathic concern, the third component includes the pro-social motivation to help others as a result of using one or both components of empathy (affective and cognitive).
As such, compassion appears to be based on both components of empathy and therefore, empathy seems to be the initial trigger of compassion and may motivate the compassionate reaction.
Evolutionary accounts view compassion as a survival affective state that is oriented toward enhancing the welfare of those who suffer, and especially intended to protect vulnerable offspring (Darwin, 1871/2004; Frank, 1988; Sober and Wilson, 1998). A central characteristic of compassion is the adjustment of the appropriate response to the target distress. Goetz et al. (2010) propose that degree of compassion is shaped by the assumptions of the observer about the other's suffering. For example, individuals and groups who are stereotypically perceived as affectionate and warm may trigger more compassion in an observer than those who are perceived as cold and aloof. Thus, because women are perceived as more warm and compassionate than men (e.g. Rudman et al., 2001; Fiske et al., 2002), their distress may provoke more compassion in an observer than will the distress of men. This assumption receives support from a meta-analysis review on helping behavior, showing that women in trouble received more help than men (Eagly and Crowley, 1986), perhaps since they evoked a higher sense of compassion.
Although compassion is central to human behavior, its biological underpinnings are largely unknown. Neuroscience studies suggest that several regions of the brain are involved in compassion, among them the interior frontal cortex, the insula and the temporal pole, which may mediate mirroring the emotions of the other; the middle and ventral prefrontal cortex involved in cognitive assessment and understanding of the other's suffering; the periaqueductal gray (PAG), substantia nigra and ventral tegmental area involved in feeling warmth or tenderness toward others; the midbrain PAG involved the perception of other's pain; and networks within the left hemisphere involved in overarching motivation to approach (for review, Goetz et al., 2010; Simon-Thomas et al., 2012). Nonetheless, studies on the neurobiological mechanisms that mediate compassion are scarce.
Because compassion is a social emotion, it is reasonable to assume that neuropeptides such as oxytocin (OT), which has been found to mediate complex pro-social, affective and tending behaviors, should play a key role in mediating compassion. OT is a nine amino-acid cyclic neuropeptide produced in the brain, which is synthesized in the hypothalamic paraventricular (PVN) and supraoptic nuclei (SON), and store and released into the brain and bloodstream from the posterior lobe of the pituitary gland. It functions as both a neurotransmitter and a hormone. OT targets are widespread across several brain regions, including the amygdala, the hippocampus, the paraventricular nucleus of the hypothalamus and the brainstem, and peripheral sites including the heart, the uterus and regions of the spinal cord that regulate the autonomic nervous system (Huber et al., 2005; Langford et al., 2006; Neumann, 2008). Moreover, OT functions as one of the hormones in the hypothalamic–pituitary–adrenal axis that mediates, among others, the stress response (Heinrichs et al., 2009; Dabrowska et al., 2011). During the past decade, ample evidence has shown that the OT mediates complex pro-social, affective and tending behaviors (for review, Heinrichs et al., 2009; Bethlehem et al., 2012; Graustella and MacLeod, 2012).
OT has been shown to play a critical role in the expression of maternal behavior across a variety of species (Uvnas-Moberg, 1998; Szyf et al., 2008; Zhang and Meaney, 2010), including human mothers (Feldman et al., 2004; Levine et al., 2007; Feldman, 2011), and in parental attachment and bonding between infants and mothers (Lee et al., 2000).
Interestingly, Taylor et al. (2000) suggest that OT is involved in sexually differentiated reactions to stress. According to this view, the familiar 'fight-and-flight' human response to stress may particularly characterize male behavior, whereas women are more likely to react to stress through social communication or 'tend-and-befriend' behaviors—the response of bonding, nurturing others and creating social networks. These behaviors, which have been suggested to be mediated by OT (Taylor, 2006; Olff et al., 2007), rely on the ability to feel compassion and have selectively evolved to maximize the survival of weaker individuals within groups. Therefore, Taylor et al. (2000) suggest those behaviors are mainly directed toward females and offspring with the intention of increasing their ability to survive and maximizing their welfare.
Throughout evolution, men were often fighters and attackers, whereas women were the caregivers and caretakers of the offspring. Nevertheless, in a safety context, as with in-group members, both men and women can show tend and befriend behavior. Recent findings suggest that OT may particularly enhance pro-social behaviors toward those with whom we feel safe and close to, and have less of an impact upon such behaviors toward people who may endanger us, i.e. in-group members vs to out-group members (Declerck et al., 2010; De Dreu et al., 2011; De Dreu, 2012).
Furthermore, current studies show that OT moderates paternal behavior and attachment bonding between infants and fathers (Feldman et al., 2010; Gordon et al., 2010a,b), and romantic attachments between men and women (Schneiderman et al., 2011). Likewise, OT enhances emotional empathy (Hurlemann et al., 2010), trust (Kosfeld et al., 2005) and recognition facial expressions (Domes et al., 2007; Fischer-Shofty et al., 2010).
As tend-and-befriend behaviors occur mostly toward women, and as it has been found that OT mediates tending and caring behaviors in both men and women, OT may enhance increased compassion in both men and women toward women targets as opposed to men targets.
Nevertheless, recent studies report inconsistent findings about the differential effect of OT and AVP on men and women. Although some of the studies found that OT affects similarly women and men both genders (e.g. Ditzen et al., 2009; Theodoridou et al., 2009; Feldman et al., 2010), other find some gender-differential effects (e.g. Domes et al., 2010; Fischer-Shofty et al., 2013; Prehn et al., 2013). As such, this study sought to examine whether OT moderates pro-social and tending behaviors in either sex, or whether OT will differentially affect women and men.
It was hypothesized that subjects' compassion toward women may be overall higher from their compassion toward men, and that OT may differentially affect compassion toward the distress of women and of men. In addition we examined whether OT enhances compassion toward women, both in men and women participants. We measured compassion using a situation that resembles real inter-personal everyday interactions: the participants were requested to listen to four recorded stories of protagonists describing distressful emotional conflicts, and then asked to briefly provide compassionate advice regarding the distressful event described in the tapes. Each story was rated on four sub-scales, taking in account four different aspects of compassion.
Soc Cogn Affect Neurosci. 2015;10(3):311-317. © 2015 Oxford University Press