Is legacy actually a boost in admission likelihood at Harvard?

Although Harvard doesn't actually release this data, people online say the legacy acceptance rate is around 30%. I'm wondering whether this is actually correlated to being legacy or if children of people who studied at Harvard are generally raised in an environment that pushes them towards Harvard (or any t20 for that matter).

In my case, my father, grandfather, great uncle, uncle, and sister all went to Harvard. Will this offer any boost for me?