Hong Kong children were happier last year despite a "worrying" decline in their ability to cope with the kind of adversity that might have led to suicides, researchers say. The child happiness index, produced by Lingnan University, rose from 6.91 in 2012 to 7.23 last year. The index maximum is 10. But a fall was seen in the scores for insight and fortitude - two of the four determinants of happiness. The other two are love and engagement. Researchers said the decline in fortitude to 6.64 out of 10 from 7.10 was "worrying and should be attended to" as it showed children might not know how to deal with situations that did not meet their expectations. Lead research professor Ho Lok-sang described the decline as "rather significant". "There were several children who committed suicide last year, which showed that the resilience of some of our children is quite weak," he said. "Parents should guide their children, starting from an early age, [on] how to deal with pressure, as it is a major source of unhappiness." To test their fortitude, the children surveyed were asked to respond to statements such as "you have the courage to face difficulties" and "you won't give up easily once you have decided to do something". To test their insight - an ability not to keep comparing themselves with others and learn from mistakes - they were asked to respond to statements such as "we don't need to be better than others, but need to try our best". The insight score dropped from 6.37 in 2012 to 6.19. The study - commissioned by the Early Childhood Development Research Foundation for the second year - surveyed 1,119 children aged eight to 17 from eight primary schools and 12 secondary schools from September to October 2013. The survey also discovered that children from poorer families tend to be unhappier. "When children want to take part in some extra-curricular activities but their parents do not have enough money to support them and ask them not to do that, there may be some conflicts within the family, thus making children unhappy," Ho said. The study also found that pressure that was generated from their schoolwork and from their participating in extra-curricular activities also poses a significant adverse impact on children's happiness.