11/30/2011 06:23 pm ET | Updated Jan 30, 2012

'Tis the Season to Notice Situations

As Thanksgiving draws to a close, we have unambiguously crossed the starting line of the holiday season. It's a time of year that predictably brings with it a variety of familiar visitors: greeting cards, gift lists, family get-togethers, and intolerable mall traffic, to name just a few. But there's yet another recurring aspect of the holidays that we don't always take note of, namely that they provide the perfect opportunity to stop and appreciate the power of situations.

What do I mean? Well, human nature is remarkably (and often surprisingly) dependent on context. While we tend to view ourselves and others around us in terms of predictably consistent personality types, time and time again behavioral science demonstrates that how we think and what we do varies dramatically by simple situational considerations like where we are. And who's around us. Or what others expect of us.

The situations in which we find ourselves shape our instincts, preferences, and actions across a wide range of domains, from decision-making in the workplace to how and when we fall in love. In fact, I've written a book on the very topic, titled Situations Matter, which comes out next month.

What does any of this have to do with the holidays (other than, of course, the obvious potential for you to start a new family tradition this year by pre-ordering dozens of copies of my book for all of your friends and loved ones)? Well, one of the fascinating aspects of the power of situations is that we so often fail to notice it. Most of us have a blind spot when it comes to the ways in which context shapes our lives, but the holidays provide an opportunity to recognize these situations that otherwise hide in plain sight.

For example, just think about the unique sensory experience of return visits to the town, neighborhood, or house in which you grew up. I still recall the first time I entered my childhood home as a visitor, over Thanksgiving break my freshman year of college. Much to my surprise, it smelled like my house, in the same way that other people's houses often had a distinct smell. And later that night, as I lay in bed, I realized that it sounded like my house too, even though prior to those moments I never would have been able to articulate that my house smelled or sounded or felt like anything in particular.

You see, we spend most of our daily existence in familiar environments, within the confines of well-worn routine. This renders us relatively oblivious to the situational influences around us. Often it's only the jolt of the unfamiliar that reminds us just how numb we are to our regular surroundings. Like the return to the childhood house. Or a trip abroad, only after which we're able to recognize the different unwritten rules (or norms) that guide social interactions back home.

The holidays do more than trigger nostalgic olfactory epiphanies-though between freshly baked goods, mulling cider, burning candles, and crackling fireplaces, this time of year is certainly a feast for the five senses and the memories we so deeply associate with them. During the holidays, we also catch a glimpse of the social contexts that have shaped who we are-contexts that we usually take for granted.

Nothing provides quite the insight into the person you're newly dating than seeing how he or she interacts with his or her family. Sometimes seeing others in their natural habitat provides the missing pieces to the puzzle in your head. As in, so that's why you always finish your meal before I'm done with my salad-it's like the Lord of the Flies at this dinner table, and for he who hesitates, seconds on mashed potatoes are lost. Other times seeing your partner with family can be shocking, as when this person you thought you knew so well seems to transform into someone else entirely right in front of you.

This power of situations is part of what makes the holidays a psychologically double-edged sword. Yes, it's wonderful to see family and other loved ones with whom we don't otherwise get to spend enough time. But it can also catch us off guard to be back in familiar physical and social contexts, suddenly opening the floodgates to long-suppressed emotions and relationships.

One minute you're enjoying the company of lazy time spent with siblings. The next minute the f-word is punctuating a debate between so-called adults over whether "Dunkin' Donuts" should count as a "store" during a round of Scattergories. Hypothetically speaking, of course...

Situations matter, a conclusion we often fail to heed. And my argument in the book is that this is a lesson that can change the way you see the world and make you a more effective person.

But it's also a lesson with clear implications specific to the holiday season. Because over the weeks to come, many of us will find the person we believe ourselves to be today in situations that conjure up the attitudes and tendencies of the persons we used to be. Few experiences in life serve as clearer reminders of just how powerful context can be.

Like this post? Interested in the book? Agree that Dunkin' Donuts is a store and that Sam's brother was wrong for voting against it as a valid Scattergories answer? Then check out the website for "Situations Matter: Understanding How Context Transforms Your World" (available now for pre-order). You can also follow Sam on Facebook here and on Twitter here. Book trailer video below: