Why a second PhD at 85 is a good idea

He had joined Monash University's medical school in its infancy in 1962, rising to become the head of the department of biochemistry and the deputy dean of medicine, and had published more than 140 research papers.

But as he approached retirement, he wasn't looking to put his feet up.

A lifelong passion for learning had him return to study at the university and radically change direction completing a bachelor of arts in psychology and sociology in 1996 and a BA (honours) in sociology in 1999.

He also became a trained marriage, relationship and grief counsellor, opened a practice in lifestyle counselling and turned his sharp mind to helping older people.

Now, at 85, he is working on his second PhD thesis 57 years after completing the first one at London University. So does a lifelong passion for learning contribute to wellbeing? "I'm sure it does it at least provides a lifetime of motivation and satisfaction which has lasted into my old age," Professor Lowther says.

"I think it is very important to be able to identify something which you have to strive to achieve when you are older. There is good sociological evidence that when older people give up maintaining social contacts the result is often apathy and loss of the will to live."

It is the thrill of discovery that he enjoys most. "The thing that keeps me going is the novelty of what you find and the pleasure it gives you to make a pattern of the problems you are looking at," he says.

"I definitely believe that my lifelong interest in research has provided the excitement of discovery with the satisfaction of getting there. It's not just the knowledge it's also the interaction with other people in many different countries who share the same passion and curiosity."