Professor David Chan, director of the SMU Behavioural Sciences Institute made a comment that we tended to place our attention on what the critical mass for Singapore should be when discussing our population issues. However, the more critical issue is interpersonal relationships. For instance, the number of people staying together in a room could be reduced by half, but if there is animosity between these room-mates, the problem still cannot be solved even with fewer people. Prof Chan offered the above view at a Conference on Integration held yesterday at the Institute of Policy Studies (IPS).