Gender Differences in Christmas Gift-Giving - APA PsycNET

Evolutionary Behavioral Sciences 2015, Vol. 9, No. 2, 140 –144

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Gender Differences in Christmas Gift-Giving Mark Dyble and Abram J. van Leeuwen

R. I. M. Dunbar

University College London

University of Oxford

In Christmas gift giving, the value of a gift is broadly representative of the strength of the relationship between gift-giver and recipient. In this study we examine the effects of relatedness, social proximity, and donor gender on self-reported patterns of Christmas gift-giving. As is consistent with kin selection and social network theory, respondents bought gifts of greater value for more closely related kin, and individuals in more proximate social network layers. Although men and women spent similar amounts on gifts for kin and close network layers, there was a striking gender difference in spending on friends and the most distant network layer, with women spending significantly more. Keywords: altruism, friendship, gender differences, gift-giving, kinship

As well as an important form of economic exchange, gift-giving is a mechanism by which individuals initiate and maintain social relationships in many human societies. The importance of gift giving is reflected in the large amount of work on the subject within the fields of anthropology (Mauss, 1954; Sherry, 1983), sociology (Caplow, 1982; Cheal, 1988), and marketing (Laroche, Saad, Kim, & Browne, 2000). More recently, gift giving has also been examined within the framework of evolutionary psychology (Iredale, Van Vugt, & Dunbar, 2008; Saad & Gill, 2003), building on a body of theoretical and empirical studies of investment strategies in nonhuman animals (Barrett & Hanzi, 2001; Colmenares, Zaragoza, & Hernandez-Lloreda, 2002; Vahed, 1998), and representing a part of the growing interest in the evolutionary basis of human consumption (Saad, 2007, 2011). A number of studies have tested evolutionary predictions in the context of Christmas giftgiving, finding significant effects of sex and

This article was published Online First September 22, 2014. Mark Dyble and Abram J. van Leeuwen, Department of Anthropology, University College London; R. I. M. Dunbar, Department of Experimental Psychology, University of Oxford. Correspondence concerning this article should be addressed to Mark Dyble, Department of Anthropology, University College London, 14 Taviton Street, London WC1H 0BW, United Kingdom. E-mail: [email protected] 140

donor-recipient relatedness on gift-giving patterns. In an analysis of self-reported gift values, Mysterud et al. (2006) found that gifts of greater value were given to more closely related individuals, that women exchanged gifts with a larger number of friends than men, and that women spent more on gifts than men did. In contrast, in an analysis of intended spending patterns, Jonason et al. (2009) found that men planned to spend more on Christmas gift giving in general than women did, although women planned to spend more on friends and family than men. In this study we aim to further explore the effects of donor-recipient relatedness and sex on patterns of Christmas gift-giving. We also aim to extend existing work by examining the effect of the strength of the social relationship between donor and recipient on gift value. In line with previous work on altruism in social networks (Curry, Roberts, & Dunbar, 2013), we predict that individuals will spend significantly more on gifts for recipients in more proximate social network layers. Method Participants and Procedure Data were gathered via an online questionnaire in which respondents were asked to provide information about all Christmas gifts they had bought, including (a) the cash value of the gift in British pounds (GBP), (b) their relation-


DYBLE, VAN LEEUWEN, AND DUNBAR

ship with the gift recipient, and (c) the frequency of contact with the recipient. Additionally, respondents provided their own age and sex. In total, 99 participants fully completed the survey, of which 38 were men and 61 were women. The mean age was 23.6 years (SD ⫽ 2.6), range 19 –31. Across the 99 participants, 562 gifts were given. Frequency of contact was recoded into a network layer variable according to a scheme used in previous studies (Curry et al., 2013; Roberts, Wilson, Fedurek, & Dunbar, 2008) where weekly contact represents layer 1 (the ‘support network’), monthly contact represents layer 2 (‘sympathy network’), and yearly contact layer 3 (the ‘active network’). The remainder form part of the inactive or ‘acquaintances’ network. Relatives were categorized according to biological relatedness (r), such that, for example, parents and siblings are r ⫽ .5, aunts, uncles, and grandparents are r ⫽ .25, and first cousins are r ⫽ .125. Analysis Because the data had a hierarchical structure, with gift recipients being nested by donor, a multilevel model was used to analyze the data (also known as a hierarchical linear model). Although gift value between 1 and 100 GBP was provided to the nearest unit, all gifts of greater value than 100 GBP were deflated into a ‘101⫹’ category. Because of this, and because

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the gift values between 1 and 99 GBP were non-normally distributed, even after transformation, the dependent variable (gift value) was split into ordinal categories by terciles. Throughout the study, alpha level was .05 and tests were two-tailed. Analysis was conducted using MLwiN 2.28. Results We constructed multilevel cumulative logit model with a random intercept. The threecategory outcome variable indicated the amount spent (in GBP) on a gift (“low” ⫽ 1 – 10; “medium” ⫽ 11 – 20; “high” ⱖ 21). Table 1 shows the distribution across gift value categories by relatedness category and network layer separately for female and male respondents. The following predictor variables were included in the initial model: sex (level 2), number of gifts bought (level 2), relatedness (level 1), network layer (level 1), as well as cross-level interactions between sex and relatedness and between sex and network layer. Number of gifts bought was not a significant predictor and so was dropped from the model. Checks of the proportional odds assumption necessitated the inclusion of separate coefficients for the different spent categories for the relatedness variable. The small number of level-1 units (recipients) per level-2 unit (giver) precluded the inclusion of random slopes for

Table 1 Distribution of Gifts Across Amount Spent Categories by Relatedness Category and Network Layer for Male Versus Female Gift Givers (Ignoring Nesting Structure) Giver gender

Recipient category

% “low”

% “medium”

% “high”

Male Female Male Female Male Female Male Female Male Female Male Female Male Female

.5 relative (n ⫽ 111) .5 relative (n ⫽ 187) .25 relative (n ⫽ 47) .25 relative (n ⫽ 78) .125 relative (n ⫽ 10) .125 relative (n ⫽ 35) Friend (n ⫽ 38) Friend (n ⫽ 56) Network layer 1 (n ⫽ 81) Network layer 1 (n ⫽ 105) Network layer 2 (n ⫽ 33) Network layer 2 (n ⫽ 90) Network layer 3 (n ⫽ 92) Network layer 3 (n ⫽ 161)

19.8 18.2 46.8 50.0 80.0 37.1 84.2 58.9 43.2 28.6 24.2 24.4 44.6 41.6

30.6 33.7 48.9 30.8 20.0 57.1 15.8 14.3 21.0 27.6 24.2 32.2 43.5 35.4

49.6 48.1 4.3 19.2 0.0 5.7 0.0 26.8 35.8 43.8 51.5 43.3 12.0 23.0


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level-1 predictors (as this would have prevented convergence). The final model is shown in Table 2. Note that a higher coefficient represents a greater probability of being in a lower gift value category. Results for the random intercept justify the use of a multilevel model (B ⫽ 1.751, SE ⫽ 0.364, p ⬍ .001). The model identified a clear relationship between spending and recipient relatedness (see Table 2). Givers spent more on gifts for .5 relatives than for .25 (B ⫽ 0.795; SE ⫽ 0.446; p ⫽ .07 for “low” and B ⫽ 1.109; SE ⫽ 0.489; p ⫽ .02 for “medium”), .125 relatives (B ⫽ 1.883; SE ⫽ 0.906; p ⫽ .04 and B ⫽ 3.679; SE ⫽ 1.211; p ⫽ .002), or friends (B ⫽ 4.227; SE ⫽ 0.656; p ⬍ .001 and B ⫽ ⫺3.562; SE ⫽ 0.677; p ⬍ .001). Additional analyses varying the reference category revealed that significantly more money was spent on gifts for .25 and .125 relatives than on friends. However, the interaction between sex and friend was highly significant (B ⫽ ⫺2.525; SE ⫽ 0.727; p ⬍ .001). The sign of the coefficient indicates that women spend more than men on gifts for friends (relative to .5 relatives). Figure 1 illustrates this interaction. With regard to the net-

work layer predictor, givers spent significantly less on gifts for individuals in network layer 3 as compared with network layer 1 (B ⫽ 1.814; SE ⫽ 0.526; p ⬍ .001). An interaction between sex and network layer 3 was found, with women spending more than men on gifts for recipients in network layer 3 (B ⫽ ⫺1.477; SE ⫽ 0.627; p ⫽ .02). Figure 2 illustrates this interaction. Discussion In this study we examined the effects of biological relatedness, social network position, and donor sex on self-reported patterns of Christmas gift giving. As in previous work on Christmas gift giving (Jonason et al., 2009; Mysterud, Drevon, & Slagsvold, 2006), gifts of greater value were bought for kin more closely related to the gift donor, conforming to the predictions of kin selection theory. Also in line with previous work (Mysterud et al., 2006), we found a sex difference in gift giving, with women spending significantly more than men on gifts for friends. Additionally, this study produced two novel findings. First, we found that, in line with social network theory, gift

Table 2 Multilevel Cumulative Logit Model for the Effects of Giver Gender, Recipient Relatedness and Its Interaction With Donor Gender, and Network Layer and Its Interaction With Donor Gender on Amount of Money Spent on Christmas Gift Parameter Female (ref: male) Network layer (reference: Layer 1) Layer 2 Layer 3 Relatedness – “low” (reference: .5 relatives) .25 relatives .125 relatives Friends Relatedness – “medium” (reference: .5 relatives) .25 relatives .125 relatives Friends Relatedness ⫻ female .25 relatives ⫻ female .125 relatives ⫻ female Friend ⫻ female Network layer ⫻ female Layer 2 ⫻ female Layer 3 ⫻ female Intercept variance Constant for “low” Constant for “medium” or “low”

B

SE

p

0.504

0.505

.32

0.507 1.814

0.537 0.526

.35 ⬍.001

0.795 1.883 4.227

0.446 0.906 0.656

.07 .04 ⬍.001

1.109 3.679 3.562

0.489 1.211 0.677

.02 .002 ⬍.001

0.638 ⫺0.689 ⫺2.525

0.541 1.014 0.727

.24 .50 ⬍.001

⫺0.368 ⫺1.477 1.751 ⫺2.277 ⫺0.705

0.643 0.627 0.364 0.427 0.408

.57 .02 ⬍.001


DYBLE, VAN LEEUWEN, AND DUNBAR

donors invested more in gifts for recipients in more proximate social network layers. Second, we found an interaction between social network layer and donor gender, with women spending more than men on gifts for recipients in more distant network layers. Taken together, these findings indicate that men are less willing than women to invest in their more extended social relationships. If this reflects a more general sex difference in investment in social relationships, and an evolved psychological disposition, why, and in what context might it have been adaptive? Migration from one community to another often triggers a major reconstruction of personal social networks, with individuals whom ego was only distantly associated being promoted to more proximate network layers. In patrilocal social systems, women are more likely than men to migrate and undergo this social network transformation, and therefore might have more to gain than men in fostering good relations with more distantly related individuals. If patrilocal social systems were commonplace during human evolutionary history, it is plausible that this could have resulted in a sex-specific psychological adaptation that still shapes behavior in evolutionarily novel contexts. Whether patrilocality was commonplace in human evolutionary history, however, is unclear. Most contemporary hunter-gatherers, for example, live in highly mobile, multilocal groups (Hill et al., 2011). Some limitations of this study should be noted. First, considerations of reciprocity, fairness,

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Figure 2. Predicted male versus female spending patterns on .5 relatives in network layer 3. Male respondents shown by the diagonal bars, females by the dotted bars.

respect, and hierarchy are also important in shaping gift-giving decisions—they are not purely a function of good-will. Reputation, gossip, and even some form of punishment might face a gift giver who deviates from what is expected of them. Second, the participants of this study represented a narrow age range of young adults. Social network studies have shown that the composition of personal social networks change over the lifetime (Saramäki et al., 2014). Further work could be done in the same context to see whether the observed sex differences persist into later life. Finally, the respondents represent what Henrich, Heine, and Norenzayan (2010) have called a ‘WEIRD’ population – Western, Educated, Industrialized, Rich, and Democratic. In this study, this bias is not just an artifact of the method of data collection but also of the subject of study itself—the kind of Christmas gift-giving we report on in this study is practiced largely in ‘WEIRD’ countries. A sample of different kinds of giftgiving in other populations would clearly be desirable. References

Figure 1. Predicted male versus female spending patterns on friends in network layer 1. Male respondents shown by the diagonal bars, females by the dotted bars.

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Received December 14, 2013 Revision received August 18, 2014 Accepted August 21, 2014 䡲