Most of the people who hang around in my think tank in Jerusalem are in their 20s and 30s. One grew up in a Chasidic family but now self-defines as non-religious and is beginning an academic career. One woman grew up in a non-observant family and was active in the peace movement and is now religiously observant and an expert on and sympathiser with the hard-core of the settlement movement.

Another woman grew up in a traditional Sephardic family and remains unself-consciously traditional while writing a doctoral thesis on the transmission of religious folklore. One fellow was raised in a secular-Zionist family and still self-defines as non-religious, but he prays with a minyan every day and observes Shabbat. Another was raised in a scrupulously religious family and remains observant, but, as a matter of principle, he refuses to cover his head with a kippah.

One fellow is a product of Kookian religious Zionism, but is now a gung-ho evangelist for full-throated capitalism. Another just completed a thesis on the phenomenon of Israeli celebrities, mostly artists and musicians, who are now loosely connected to various Jewish spiritual groups, most prominently Breslov, and are observant in a variety of idiosyncratic ways, but refuse to self-define as either religious or non-religious.

You might find any one of these life choices laudable or lamentable, but that’s not the point. The phenomenon is interesting in aggregate. There seems to be a great deal of fluidity here, and the fluidity is strangely painless. These people are comfortable with themselves and with each other. What’s this all about?

One important aspect of the answer has to do with what is known as signalling. All societies, especially tight-knit ones, require that members make some sort of public display of sacrifice on behalf of membership in the group. This is a way of proving loyalty to the community and serves to weed out free riders, who wish to reap the benefits of membership without undertaking the obligations. Such signals, as they’re called, are ubiquitous.

If you’re a banker and want to signal potential depositors that you’re not running off to Brazil with their money next week, build a big marble building, since that kind of investment is worthwhile only if you intend to be in business for a long time. If you’re a gang member and want to signal to your colleagues that you’re not planning to grow up and go all middle-class on them, tattoo “SATAN” on your forehead.

Jews are particularly fond of such things. In fact, we’ve grown so accustomed to the centrality of signaling in Judaism that we can hardly imagine what Judaism would be like with less of it. We wear shtreimlech or hats or kippot of a certain colour or none of the above, we pray in this synagogue but never in that one, we use the right dialect of Yinglish and the appropriate accent, we eat here but not there, we flaunt our very special family customs, we bagel, we batel, we battle.

We are so used to Judaism being spoken self-consciously like a second language that we are perplexed when we see the early signs of the return of Judaism spoken naturally, like a first language.

Young Israelis like the men and women in my office aspire for Judaism to be a culture, not a counter-culture. They don’t need to prove they’re not assimilating; there aren’t enough non-Jews here to assimilate into. They have no interest in wasting energy on broadcasting their loyalty to this box and not that box.

That mix-and-match of modes of dress, outlook and practice that seems incongruous to old fogies and diaspora Jews are simply inchoate attempts at breaking down the boxes and separating the signals from the substance. These young people are looking for some form of authentic Judaism rich enough, substantial enough, realistic enough to serve as a national culture and not merely as a counter-culture sufficient to sustain a minority.

If I might borrow a business term, they are looking for a version of Judaism that scales. This will happen slowly and from the bottom up; it will involve dead ends, intellectual fads, and ill-considered compromises. But the trend is positive.

Already there are some small, tentative steps in interesting directions. Galgalatz, the radio station that determines Israel’s Top 40 hits, includes in its playlist songs that break down all the boundaries between secular and religious music, seamlessly combining eastern and western religious liturgy with contemporary folk and rock styles. Literary awards go to books that straddle the boundary between secular and religious literature in a fashion reminiscent of that of Israel’s first Nobel laureate, S. Y. Agnon. Safed and Jerusalem are flush with galleries purveying serious (and not serious) contemporary art with profounder Jewish content than Chagall. This isn’t much, but it’s a start.

Excerpted from Judaism Straight Up: Why Real Religion Endures, Moshe Koppel, published by Maggid Books, £19.73 hardback, £5.95 Kindle

Moshe Koppel is a professor of computer science and chairman of the Kohelet Policy Forum