NEW DELHI, Dec. 25 -- With absolute indelicacy, Wikipedia defines old age as "ages nearing or surpassing the life expectancy of human beings and is thus the end of the human cycle." Reinforcing this sombre hypothesis, neuroscience suggests that the brain volume diminishes over time at 5 per cent every decade from the 30s, especially that part of the brain that regulates executive functions and leadership qualities such as problem-solving or goal setting. The decline in aptitude and mental processing speed results in dysfunctions such as unconscious repetition of thoughts and behaviour and an erratic memory. (Mercifully, culling is not applied to humans; otherwise, we geriatrics would be foremost in line to the chopping block for the expen...