Compassion is putting yourself in the other person's shoes and feeling sympathy. It does not require affection. One might feel compassion for Hitler, Stalin or Saddam on learning about their appalling childhoods (like most famous dictators, they lost a parent before the age of 14), or even for George Bush (who had a beastly time), but still hate them for what they did.
The potential in the developed world for compassion, both within individuals and in our societies, has never been greater. Once starvation and disease are under control, there's more space to consider other people's predicaments. And in some respects, our societies are more compassionate. Welfare provisions protect our most vulnerable citizens. Annually, we approve the handing over of significant (albeit not significant enough) chunks of aid and money to poor nations by our rulers.
That levels of compassion among societies vary so much proves its extent is largely determined by social structures. At an individual level, it is hugely influenced by early childhood care. Studies of adopted children prove that their capacity to adopt another person's standpoint and sympathise, correlates closely with how badly they were treated before being separated from their (usually maltreating) parents, the amount of time they spent in institutions, the quality of care while there and the subsequent quality of foster or adoptive parents. The younger the age of adoption and the better the subsequent care, the greater the capacity for compassion.
Recent studies (see Paul Gilbert's book, Compassion) show that compassion has electro-chemical correlates in the body which presumably evolved over many millennia. When our biological need for safety is satisfied, neuropeptides, such as oxytocin, put us in the frame of mind to be compassionate.
As Gilbert points out, cruelty is the opposite of compassion - you take the other person's standpoint in order to know what will cause distress. It has its own biological correlates and can be fostered or inhibited by social forces.
Given that the last century gave us Hitler, Stalin and Pol Pot, it is important not to exaggerate the extent of modern day cruelty within western European and Anglo-Saxon nations. It is now more subtle, but very much on the increase.
For instance, 'cruel TV', such as Big Brother, humiliates participants and encourages humiliating behaviour in viewers. In Britain, the seeds of this poisonous dropsy were sown by 'yoof' series such as The Word and The Big Breakfast, which offered a disastrous model to young people, often making fools of the people who took part; while the Survivor series has plumbed new lows - pitted against each other, the scantily clad survivors engage in vicious office politics.
How the compassionate potential our genes confer upon us should be fostered is ultimately a matter for our rulers. It is vital that they use legislation to create the conditions in which we have the spare capacity to feel for each other.