Here are half a dozen recent research studies that caught my eye.  Diener et al, in a large sample of people round the world, found intriguingly that wealth tends to increase life satisfaction, while it is the fulfilment of psychological needs - learning, autonomy, using one's skills, respect, and the ability to count on others in an emergency - that better predicted positive feelings.  Quoidbach & colleagues took this a stage further showing that " ... money impairs people's ability to savor everyday positive emotions and experiences. In a sample of working adults, wealthier individuals reported lower savoring ability (the ability to enhance and prolong positive emotional experience). Moreover, the negative impact of wealth on individuals' ability to savor undermined the positive effects of money on their happiness".  Delightfully they reported "We found that participants exposed to a reminder of wealth spent less time savoring a piece of chocolate and exhibited reduced enjoyment of it compared with participants not exposed to wealth" - the practical advice you do get on this website!

Shifting to a couple of interesting recent studies on relationships with others, Kavanagh et al in their paper "The mating sociometer: a regulatory mechanism for mating aspirations" found a fascinating lack of connection between mating self-esteem and friendship self-esteem.  While Gilet et al in their study on "Selfish or servant leadership" - admittedly only in coordination game observations - commented "Our results support the evolutionary hypothesis that leadership is a social good for the group: leadership benefits followers but is potentially costly for the individual taking on the leader role. Across the two economic games leaders do less well - earn less money - on average than followers. Furthermore, social participants choose to lead more often than selfish participants and there is no relationship between leadership behavior and personal dominance".  As a rather impoverished extrovert, I'm not quite sure how to react to this report.

Finally there are a couple of studies on more intrapersonal issues.  Raes's paper "Rumination and worry as mediators of the relationship between self-compassion and depression and anxiety" reports that self-compassion's positive influence on psychological distress is partly mediated by its effects on unproductive repetitive thinking.  And Barber et al in  "Affect regulation strategies for promoting (or preventing) flourishing emotional health" highlight that " ... in order to achieve flourishing, individuals may need to reduce avoidance strategies and increase engagement strategies".  Both these papers add to other recent literature also demonstrating links between mindfulness, self-compassion & reduced depression, and between behavioural activation & increased wellbeing.       

Diener, E., W. Ng, et al. (2010). "Wealth and happiness across the world: material prosperity predicts life evaluation, whereas psychosocial prosperity predicts positive feeling." J Pers Soc Psychol 99(1): 52-61.  [PubMed] 
The Gallup World Poll, the first representative sample of planet Earth, was used to explore the reasons why happiness is associated with higher income, including the meeting of basic needs, fulfillment of psychological needs, increasing satisfaction with one's standard of living, and public goods. Across the globe, the association of log income with subjective well-being was linear but convex with raw income, indicating the declining marginal effects of income on subjective well-being. Income was a moderately strong predictor of life evaluation but a much weaker predictor of positive and negative feelings. Possessing luxury conveniences and satisfaction with standard of living were also strong predictors of life evaluation. Although the meeting of basic and psychological needs mediated the effects of income on life evaluation to some degree, the strongest mediation was provided by standard of living and ownership of conveniences. In contrast, feelings were most associated with the fulfillment of psychological needs: learning, autonomy, using one's skills, respect, and the ability to count on others in an emergency. Thus, two separate types of prosperity-economic and social psychological-best predict different types of well-being. 

Quoidbach, J., E. W. Dunn, et al. (2010). "Money Giveth, Money Taketh Away." Psychological Science 21(6): 759-763.  [Abstract/Full Text]
This study provides the first evidence that money impairs people's ability to savor everyday positive emotions and experiences. In a sample of working adults, wealthier individuals reported lower savoring ability (the ability to enhance and prolong positive emotional experience). Moreover, the negative impact of wealth on individuals' ability to savor undermined the positive effects of money on their happiness. We experimentally exposed participants to a reminder of wealth and produced the same deleterious effect on their ability to savor as that produced by actual individual differences in wealth, a result supporting the theory that money has a causal effect on savoring. Moving beyond self-reports, we found that participants exposed to a reminder of wealth spent less time savoring a piece of chocolate and exhibited reduced enjoyment of it compared with participants not exposed to wealth. This article presents evidence supporting the widely held but previously untested belief that having access to the best things in life may actually undercut people's ability to reap enjoyment from life's small pleasures.

Kavanagh, P. S., S. C. Robins, et al. (2010). "The mating sociometer: a regulatory mechanism for mating aspirations." J Pers Soc Psychol 99(1): 120-132.  [PubMed] 
Two studies (Ns = 80 and 108) tested hypotheses derived from Kirkpatrick and Ellis's (2001) extension and application of sociometer theory to mating aspirations. Experiences of social rejection-acceptance by attractive opposite-sex confederates were experimentally manipulated, and the impact of these manipulations on self-esteem, mating aspirations, and friendship aspirations was assessed. Results indicated that social rejection-acceptance by members of the opposite sex altered mating aspirations; that the causal link between social rejection-acceptance and mating aspirations was mediated by changes in state self-esteem; and that the impact of social rejection-acceptance by members of opposite sex was specific to mating aspirations and did not generalize to levels of aspiration in approaching potential same-sex friendships. This research supports a conceptualization of a domain-specific mating sociometer, which functions to calibrate mating aspirations in response to experiences of romantic rejection and acceptance.

Gillet, J., E. Cartwright, et al. (2010). "Selfish or servant leadership? Evolutionary predictions on leadership personalities in coordination games."  Personality and Individual Differences. In Press, Corrected Proof.
We study the personalities of emergent leaders in two coordination games in groups of four players each with monetary incentives. Our results support the evolutionary hypothesis that leadership is a social good for the group: leadership benefits followers but is potentially costly for the individual taking on the leader role. Across the two economic games leaders do less well - earn less money - on average than followers. Furthermore, social participants choose to lead more often than selfish participants and there is no relationship between leadership behavior and personal dominance. Our results support the idea that leadership can be servant rather than selfish and we note the implications of this finding.

Raes, F. (2010). "Rumination and worry as mediators of the relationship between self-compassion and depression and anxiety." Personality and Individual Differences 48(6): 757-761.  [Abstract/Full Text] 
The mediating effects of rumination (with brooding and reflection components) and worry were examined in the relation between self-compassion and depression and anxiety. Two hundred and seventy-one nonclinical undergraduates completed measures of self-compassion, rumination, worry, depression and anxiety. Results showed that for the relation between self-compassion and depression, only brooding (rumination) emerged as a significant mediator. For anxiety, both brooding and worrying emerged as significant mediators, but the mediating effect of worry was significantly greater than that of brooding. The present results suggest that one way via which self-compassion has buffering effects on depression and anxiety is through its positive effects on unproductive repetitive thinking.

Barber, L. K., P. G. Bagsby, et al. (2010). "Affect regulation strategies for promoting (or preventing) flourishing emotional health." Personality and Individual Differences 49(6): 663-666.   [Abstract/Full Text]
This study examined affect regulation styles that best discriminated among affectivity groups representing languishing, moderate, and flourishing emotional health. Using the Measure of Affect Regulation Styles (MARS; Larsen & Prizmic, 2004) with 380 undergraduate students, analyses revealed nine affect regulation strategies (i.e., understanding/analyzing feelings, making plans, talking to someone, doing something enjoyable, being grateful, alcohol use, caffeine use, treating oneself, and consulting an advisor/mentor) that significantly distinguished between languishing and non-languishing individuals (moderate and flourishing) and six affect regulation strategies (i.e., withdrawal, emotion suppression, keep to themselves, downward social comparison, eating something, and daydreaming) that significantly distinguished flourishing individuals from those with moderate emotional health. Significant differences between moderate and flourishing groups consisted of behaviors that 'prevented' rather than 'promoted' flourishing (e.g., behavioral and cognitive avoidance). These findings suggest that in order to achieve flourishing, individuals may need to reduce avoidance strategies and increase engagement strategies.