What happens before we have a thought?

What is the impact of being a child in a home where a sibling has a chronic medical condition? What happens before we have a thought? How bad are processed foods for us? And how can a woman give birth to twins that have different fathers? Dr Chris Smith and Relebogile Mabotja have the answers. Like this podcast? Please help us by supporting the Naked Scientists (thenakedscientists.com/donate)