Babies who are repeatedly left to cry, are at risk of brain damage, and developing problems in later life.

Claims that are set out in a new Childcare book this week

Crying is a baby's sole way of signalling when he or she is uncomfortable or distressed, adding that being left crying hard is stressful, and continued acute stress sets up a hormonal chain reaction that ultimately stimulates the adrenal glands into releasing the "stress hormone" cortisol. Long continued or oft-repeated crying can produce so much cortisol that it can damage a baby's brain.

According to Penelope Leach, some young babies do not have the mental equipment to "learn" to go to sleep at the right time, so leaving them to cry is pointless.
That doesn't mean that a baby should never cry or that parents should worry when it does. All babies cry, some more than others. "It's not crying that is bad for babies, but continual crying that gets no response," she said.

http://www.guardian.co.uk/society/2010/apr/21/leaving-baby-to-cry-brain-development-damage

http://news.bbc.co.uk/1/hi/education/8636950.stm

Someone really should get that Penelope Leach a new shovel so she can dig even more deeply when looking for guilt to bury new parents under.

Of course babies cry and of course it is distressing, not only for them, but also for their parents too. But nothing is any where near as distressing as this little Miss Perfect Penelope's views usually are.

It's probably true in theory. Just like drinking coke is bad for you in theory. But for most people the effects would be negligible or non-existent.

I think if you baby was crying constantly all night you'd realise something was wrong and have it dealt with. But comforting them as soon as they cry is just training them to cry more.

No idea about the coke kallog (I don't even use the a-cola variety) but your second statement is of course what most people do- and the kids are better for having learned a regular sleep pattern..