Intended for healthcare professionals


Dynamic spread of happiness in a large social network: longitudinal analysis over 20 years in the Framingham Heart Study

BMJ 2008; 337 doi: (Published 05 December 2008) Cite this as: BMJ 2008;337:a2338

Personal view

There are 2 episodes in my life that would give weight to the above

1. When I moved to the town I live now, I was very happy to be there but
amazed that everyone who walked past seem to smile at me. It only took a
short time to prove that it was their smiled respnse to my smile that was
the reason.

2. In another more distant time, I was quite depressed, and found that
walking up a corridor the automatic door would not open for me, although
it would for anyone else walking up the same corridor ... This happened
over some weeks and did little for my self-esteem. It was only later that
I realised that I was walking along the edge of the corridor, and the
others were walking confidently in the centre and that I was missing the

Happiness (and sadness) is indeed infectious.

Competing interests:
None declared

Competing interests: No competing interests

08 December 2008
Michael Tooth
Sandy Bay, Tasmania, Australia