A smaller age gap allows children to grow closer while they are young and often leads to the closest relationship when siblings are adults. The closer children are in age, the more likely they are to bond when they are young. Although there is a chance of rivalry between siblings, they are still more likely to become closer than siblings further apart and remain close in adulthood. My brother and I are 18 months apart, and I agree that being closer in age makes siblings closer as they grow older. He is someone that I can confide in, and I think we wouldn’t be able to talk to each other about things like that if we were further apart in age. That, along with research linked below, shows that siblings do have a closer bond based on how far apart they are in age.