Extraversion and Happiness
One of the most robust findings in personality psychology is that people who are more extraverted also tend to feel happier. And by "happier", which I'm using as shorthand, what I really mean is "high activation positive affect", e.g., feeling excited, enthusiastic, energetic and lively. Psychologists, however, have had more difficulty explaining exactly why it is that people who are more talkative, bold and assertive experience more happiness than their more quiet, reserved and passive counterparts.
One class of structural explanations suggests that it's something that extraverts have that explains their greater happiness. Perhaps extraverts just have a higher biologically determined "set-point" or fixed level of happiness. Or maybe extraverts "get more bang for their buck" and experience a stronger positive reaction when good things happen to them.
A second class of explanations proposes a role for social processes. The social activity hypothesis suggests that since extraverts are more sociable, and social activities tend to be enjoyable, their increased quantity of social activity explains why extraverts tend to feel happier. However, a particularly strong study showed that the amount of time spent in various social situations only explained about a sixth of the relationship between extraversion and positive affect.
Studies employing a "counter-dispositional behaviour" paradigm present a further difficulty for all of these explanations. In these studies, participants are instructed to act extraverted, act introverted or given no acting instructions during a group discussion task. A consistent finding that has emerged is that participants report feeling happier after acting extraverted than after acting introverted, and that surprisingly, this applies for dispositional introverts and extraverts alike!
These studies show that the quantity of social experience can't explain this relationship because all participants spent the same amount of time interacting. And structural explanations also can't explain why simply acting like an extravert is enough to increase one's momentary levels of happiness. This suggests that it's the extraverted behaviours - in other words, what extraverts do - that cause increased happiness.
This still doesn't tell us much about how one gets from being talkative to feeling excited, but a recently published study finally sheds some light on the processes that may be at work here.
A Social Quality Explanation
Smillie and colleagues (2015) first surveyed 225 undergraduates and showed that social wellbeing, a measure of the quality of one's social life, explained a third of the relationship between extraversion and positive affect. This effect was driven almost entirely by one dimension of social wellbeing, social contribution, a person's sense of having an influence on their social world, or having something valuable to give to society.
Since the correlational design of Study 1 could not establish causality, Smillie et al. ran a counterdispositional behaviour experiment for Study 2. In groups of 3, 81 undergraduate students completed two fun problem-solving tasks. One participant was instructed to act extraverted (i.e., bold, talkative, energetic, active, assertive, adventurous), another was asked to act introverted (i.e., reserved, quiet, lethargic, passive, compliant, unadventurous), and a third participant was given no acting instructions.
Consistent with previous research, participants who acted extraverted experienced more positive affect than participants who acted introverted, whether they were naturally more extraverted or introverted. But the key contribution of this study was in revealing that perceived contribution to discussion tasks explained 70% of the effect of acting extraverted on positive affect. In other words, participants who were acting extraverted felt happier because they felt that they contributed more to the group activities.
So, it looks like social processes do matter - but instead of the mere amount of time spent with others, it's the qualitative aspects of social experience that help to explain the relationship between extraverted behaviours and positive affect. Specifically, this study suggested that one reason why extraverts (and pseudo-extraverts) feel happier is that extraverts feel that they are contributing more strongly to their social world. A follow-up Honours thesis (not yet published) also replicated this effect and found that it extended to another mediator, social power - an individual's perception of their ability to influence others in a social context.
This is interesting - but before extrapolating further, we'll need to consider a couple of limitations. First, like all other studies using the counterdispositional behaviour paradigm, participants were university students. This means that further research is needed before it's safe to generalise that all people feel happier after acting extraverted. And it's especially important considering that the explanation for the extraversion-happiness link may vary depending on age. For example, as Smillie et al. suggest, it's plausible that social coherence, one's ability to make meaning out of social affairs, could have a stronger effect on positive affect for older adults.
A second limitation is that it's unclear whether the difference in positive affect was due to the happiness-boosting effects of acting extraverted, or the happiness-lowering effects of acting introverted. After all, it can't be much fun to be asked to be quiet, reserved and lethargic while being dominated by an extraverted participant and another participant who tends to act quite extraverted in this context anyway. Yet, there seems to be a lack of research on how acting extraverted makes other people feel ("affective presence"), compared to how it makes the extravert (or pseudo-extravert) themselves feel.
Similarly, at the Positive Psychology Interest Group Journal Club a few weeks ago, some suggested that the instructions for acting introverted were overly-negative. Maybe - but according to the dominant Big Five descriptive framework of personality, these are more-or-less the terms that describe introverted behaviours. Being introverted does not actually mean being "introspective" or "imaginative", although popular misconceptions abound regarding what introversion is.
Should Introverts Act More Extraverted?
A final few caveats on whether it's a good idea to act more extraverted. First, extraverted behaviours are most reliably linked to activated positive affect states and are unrelated to "deactivated" positive affect states (e.g., calm, relaxed, at-ease); states that some people may see as more long-lasting, valuable end-goals.
Second, how a person feels is of course only one component of wellbeing, and this research does not say much about the effect of extraverted behaviours on, say, one's perceptions of meaning and purpose in life (although it's also worth noting that positive affect does predict an increased sense of meaning). Smillie et al. do show that extraversion predicts positive affect via one's sense of social contribution - an important aspect of wellbeing - but there is clearly plenty of scope for further research to clarify the nature of the relationship between extraversion and wellbeing more broadly construed.
Third, whereas there's been no evidence to suggest that acting extraverted incurs costs for introverts (interestingly, extraverts do seem to suffer cognitive costs after acting introverted), no research has investigated the long-term effects of counterdispositional behaviour, as it's possible that extended periods of acting extraverted could be more challenging for introverts. Brian Little has a lot more to say about the need for "restorative niches" after acting out of character.
Taken together, however, Smillie et al. contribute a valuable new perspective on why it feels good to be or act like an extravert. And despite the need for further investigation with broader samples, in everyday life, and across longer periods of time, I'm excited by the optimistic view that these studies present. It looks like happiness isn't dependent on a fixed property specific to dispositional extraverts, but is something that anyone can experience more of - and that it might be as simple as strategically choosing to act more extraverted when the situation calls for it.
Smillie, L., Wilt, J., Kabbani, R., Garratt, C., & Revelle, W. (2015). Quality of Social Experience Explains the Relation Between Extraversion and Positive Affect. Emotion DOI: 10.1037/emo0000047