Tomorrow I’ll be ringing in the winter solstice with my wife at Breitenbush Hot Springs. There will be poetry, yoga, maybe some ecstatic dancing of some kind–who knows? I’ve never been to a Breitenbush solstice, but I loved spending some time there last year and I think it’s extremely likely I’ll have a good time.

One thing I bet I won’t hear, given the circles I travel in, is many references to the birth of Jesus or other Christmas-related greetings. That’s not a problem for me–in fact, I far prefer it. I consider Christmas the most debased festival in the liturgical calendar (and anyway, as a Quaker, I feel a scruple about observing any religious holidays at all).

My friends’ silence might seem curious at first blush, given that practically all of my close friends are culturally Christian if not nominally Christian. Most today would not consider themselves Christians of any stripe: my friends are atheists, agnostics, spiritual tourists, a’la carte Buddho-Hindu-Taoists, Sufi-curious, and neopagans. But, aside from the Friends in my Quaker meeting, I can’t think of many who regard Christianity sympathetically today.

Frankly, the Christian movement–which has been an accomplice of oppression and intolerance at least as often as it has worked to bring peace and justice to the world–deserves plenty of opprobrium. To say it in Christian language, The Church has been so soiled by the world that it has departed from Christ. So I’m not surprised to have friends who may have been raised in a Christian church who today distance themselves from what they regard as a fountainhead of exploitation.

But what I do find curious is how often my friends and acquaintances–even many of those who consider themselves atheists–engage in behaviors that might be considered reverent or even spiritual. While I know a few people whose atheism is so deeply held that they are able to see all ceremony as ridiculous, more often people seem to gravitate towards reverence even if they reject the particular rituals they grew up with.

One of the most important books I read this year explores this phenomenon: David Sloan Wilson’s Darwin’s Cathedral. Wilson’s thesis is that religious behavior is evolutionarily adaptive, that our urge to find sacredness in the world is a way of enforcing group cohesion and eliciting altruistic behavior. This thesis is radical in biology circles, partly because it depends on a concept of natural selection that acts on groups as well as on individuals. It’s beyond the scope of this post to unpack the reasons this idea is derided by most biologists (nor why I believe it is correct); for now I’ll just offer a quote from David Sloan Wilson and his co-author E.O Wilson (no relation) that summarizes the entire argument behind group level selection: “Selfishness beats altruism within groups. Altruistic groups beat selfish groups. Everything else is commentary”.

Friends, I wish you well this holiday season. If you believe that altruism exists, I urge you to practice it. If you believe that altruism does not exist, I urge you to look harder. May you one day find yourself practicing altruism unawares. I wish you happiness in this season, not on account of the solstice, nor on account of the birth of Jesus (who was very unlikely to have celebrated his birthday on December 25), but on account of the biology of our species, on account of the deep urge to be kind to one another, in spite of the ways I fall short.