In the fall, the Yale Hunger and Homelessness Action Project and a host of other campus organizations joined together to raise over $30,000 to help keep the New Haven Overflow Shelter open just a few months longer over the winter.

For those few months, 125 men — some mentally ill, many slighted by a lack of affordable permanent housing — could escape crime, misery, frigid temperatures and unforgiving wooden benches for clean sheets and cozy mattresses.

Who were these students, the denizens of the notorious Yale bubble who managed to care enough to effect change outside of it? Was this service a kind of backward vindication for those who’ve been insisting that Yale and New Haven are practically the same thing?

This wasn’t the first time Yalies extended a helping hand to the surrounding city. Dwight Hall has some six dozen service organizations — many serving tutoring alone — and this doesn’t include the President’s Public Service Fellowship, Obama Works community sweeps or various outlets for service learning. There’s even a special sophomore retreat called FOCUS on New Haven whose purpose is to open eyes to the 29 non-Yale wards and 123,000 non-Yalies who just so happen to live in our backyard.

We have to ask ourselves, though: In terms of creating long-term change, are we doing enough?

Yes — perhaps. The 25 percent annual turnover rate among students who are idealistically driven and seek the purposive benefits of community service may be enough to sustain a movement like Shelter Now, but only for as long as group leaders can run the organization smoothly.

For our activist movements to grow, flourish and stand fast in the face of chance and change, we need more than goodwill and charity.

Sure, charity is all parts positive, and its agents should not be criticized. But so long as charity is freely given — something we feel it would be nice to do but not necessarily bad not to do — then something is missing. What we really need is solidarity. There must be no us and them — no “other” who reaps the benefits of our loving labor. There must only be us. Us: the homeless, the disadvantaged, the mentally ill, the young, the old and Yale.

Solidarity implies a dynamic tie between giver and receiver. “Need” is no longer a one-way street: Not only do the homeless need help from those with resources and skill, but we, the agents of change, need to offer such help. This latter need is not a matter of supererogation, a requirement to spread utility. Rather, the need is self-generated, self-fulfilling, visceral.

Maybe we’re approaching this point — maybe Beth Reisfeld ’09, Eliza Schafler ’09 and the other inspirational leaders of Shelter Now’s fall campaign were able to spice up the campus with some bona fide New Haven solidarity. Maybe not. In either case, it’s our duty to reflect on who we are as Yalies and who we want to be.

Go to the activities bazaar, or just try to fit in as a transfer student, and you’ll soon realize Yale is all about groups — societies with special induction ceremonies, all-purpose communal living spaces, a cultish marching band and, arguably, one giant exclusivist culture that fits in its own iridescent, translucent sphere.

For sure, groups are powerfully adaptive things — just ask evolutionary social psychology, Thomas Hobbes, the One Campaign or the Yes We Can coalition.

But groupiness comes with a price. Cross-cultural research shows that people of collectivistic cultures — among others, those of Japan, China and numerous hunter-gatherer societies — have lots of concern for people of their various ingroups, but compared to people of individualist cultures — the poster child being America — collectivists have less concern for people universally.

Is groupiness — and, in turn, ingroupism — at Yale thwarting the solidarity that could be had among campus and community? It’s a question we should be asking ourselves every day — whenever we experience the unfettered joy of a YPU party dinner, residential college outing or naked run through Bass Library.

This is not to say we should force ourselves to feel anxious and guilty whenever we have fun. We should simply be mindful of the effects of ingroup solidarity on solidarity among all. The stakes are too high: In the case of Shelter Now, a floundering state budget calls desperately for some other means to put roofs over undeservingly frozen heads.

The busyness and exigencies of college life require that such mindfulness be backed by institutional action. Change can be in terms of scale — the FOCUS program, for instance, could do more to advertise and attract students, and could be offered twice during the summer. Efforts can also be made to increase the salience and urgency of the community issues at hand. Why not open a homeless shelter on campus, like the one Harvard has had for 25 years?

Perhaps, most importantly, once we graduate, armed with the activist ideas and vigor to change the world, it is our duty — for at least some of us — to descend from our intellectual pedestals and serve as role models for the sort of solidarity-minded work that could be useful from New Haven to Mumbai. Might community organizing be a good start?

Dwight Hall and Shelter Now have shown what a group of strong community-minded wills can do, and our moral-attentional circle is ever broadening. But progress is never finished. With a conscious effort to re-evaluate our service values, we can bring change to our campus culture, our community and our world.

James Cersonsky is a sophomore in Ezra Stiles College.