Could genetics pave the way for developing schizophrenia or Alzheimer 's disease? Is there a genetic link between optimism and obesity? Is it ethical to screen people's DNA? Plus we find out what a nap might do for your memory, how a new study is turning addiction treatment on its head and we unravel what it means to be human. Plus we unzip whether DNA might make for an extremely high IQ! Like this podcast? Please help us by supporting the Naked Scientists