According to Thomas Perls, the director of the New England Centenarian study at Harvard University, dying at 100 is qualitively different from dying at 80. Dr Perls's research suggests that for the "oldest old", extended life is usually not the gradual deterioration, increasing decreptiude and vanishing independence that most people fear as they age. Instead centenarians remain more compos mentis; they are healthier; they go into hospital less; and they require less care than those who are struck down in their 70s and 80s.