TWICE a week, I cycle through my local park. Near the middle is an old bandstand. Every time I come to it, the old philosophical conundrum of freewill and determinism pops into my over-stimulated mind. Will I negotiate the bandstand by going clockwise or anti-clockwise? My cogitation and calculation is so rapid in my determination to demonstrate that my will is indeed free that I have been known to wobble dangerously with indecision, although, to date, I have not actually fallen off.

This week there was even greater danger, because I was factoring in a new element, this time more sociological than theological. What if the determinant factor was cultural?

This musing was prompted by a report from the Charities Aid Foundation (CAF) that the over-60s are now more than twice as likely to give to charity as the under-30s. Charities are worrying about the growth of a "donation deficit" as the oldies die off. Half of all charity income now comes from the over-60s.

The study offered an interesting potted history of change. It covered four distinct groups: the Inter-War Generation (born between 1925 and 1945), the Baby Boomers (1945-66), Generation X (1965-81), and Generation Y (1982-99).

Those born between the wars grew up in a world in which religion and wartime social solidarity were dominant cohesive forces. Their children, born into ever-rising affluence, developed a more individualist vision in which idealism and altruism went hand in hand with a more self-focused vision of life. But both religion and socialism, which offered easily understood ways of talking about our interdependence and responsibilities, have withered.

Previous CAF surveys have shown that religious donors give twice as much as those without a faith. And wealthy people give a smaller percentage of their income to charity than the less well-off do. As any Christian Aid collector will confirm, you often raise more money from poorer areas than affluent ones.

The cultural perspectives and political experiences that shaped Generation X were those of change. The global energy crisis and recession of 1979 was followed by the arrival of Margaret Thatcher. After the fall of the Berlin Wall came economic boom. Greed was good. The self-interest embodied in the market was announced as the only basis for growth, freedom, and civilisation. In the "me" generation of the '80s it became thinkable that there was "no such thing as society".

Generation Y are less maniacal, but, as the first children to grow up taking modern technology for granted, they are tech-savvy and gadget-mad. Their insatiable thirst for the next generation of smartphone, netbook, and virtual-reality feeds cycles of material dissatisfaction which commercial pressure seems constantly to ratchet up.

Though they seem confident, achievement-oriented, and ambitious, they feel a sense of entitlement which has been thwarted by a dearth of good jobs, by tuition fees, and by the ever-rising cost of getting on to the housing ladder - not to mention the high cost of binge drinking.

Social togetherness and a sense of the common good are in decline. Individualism, materialism, and a rights culture are ascendant. The present Government had a phase of loudly championing philanthropy, but ministers have stopped talking about it now, after finding they were spitting in the wind.

Perhaps I am being a grumpy old man. Maybe young people will reconnect with the notion of altruism and social solidarity if charities can only find a way of tapping into them through Twitter and other social media. Perhaps they need to turn their bikes and start cycling widdershins.