generate questions: In 2013, a study found that mixed breeds live on average 1.2 years longer than pure breeds, and that increasing body-weight was negatively correlated with longevity (i.e. the heavier the dog the shorter its lifespan).
Mutts, dogs that have several breed characteristics, live how much longer than purebred dogs? {sep_token} Do bigger dogs typically have longer or shorter lives? {sep_token} When was a study done that discovered mixed breeds tend to live longer than pure breeds? {sep_token} Typically, how much longer do mixed breeds live?