Giving money or resources to your children or aging parents is likely to increase their life span, according to a new paper published Monday in the Proceedings of the National Academy of Science. There is a linear relationship between the amount and frequency of wealth transfers and the lengths of individuals' lives, the study results have shown. The researchers' goal was to track data on how every individual in a given society consumes and saves. Intergenerational wealth transfers can include money, but they can also include houses, benefits or time. The researchers recognized that other factors - such as country's gross domestic product (GDP) and income inequality - also affect a population's life expectancy and adjusted their models to include those factors. One likely reason, [lead study author Tobias] Vogt said, for the correlation between countries experiencing greater longevity in the presence of financial transfers was that those countries exhibited stronger social cohesion. To back that up, he cited a 2010 meta-analysis ... with an aggregate of 148 separate studies involving a total of more than 300,000 participants. It found that survival was 50% greater for those with stronger social relationships compared to those with lesser or no social bonds. Generosity and life expectancy are among the six variables scientists look at when making the World Happiness Report, which is released annually by the Sustainable Development Solutions Network for the United Nations.