New research shows parents tend to stop investing and saving on behalf of children as the children reach school age.

Boring Money surveyed more than 4,000 adults, and found that two-thirds of those with children aged 3 and under were saving or investing for them. This figure gradually falls to 54 percent of parents doing so on behalf of secondary school age children.

Grandparents, however, were more likely to put money into accounts on behalf of grandchildren as the ...