Are people led by the head or by the heart? How rational are we? And how do we perceive the world? We like to say that all human behaviour could turn up in The Human Zoo, including yours.

In the last episode of the series - how does advice work? The government tells us to cut down on sugar in our diets. Obama suggests Britain should remain committed to the EU. And poor Greece has been inundated. How, psychologically, do we receive this 'expert' advice? When do we accept it and when do we ignore it?

And what about advice from friends, especially the unasked-for kind? On relationships, how to live your life, what job to take - we find it annoying to hear and take on - but why? And at the same time, we can't resist dolling out what we think are our wise words of wisdom.

Michael Blastland investigates, with resident Zoo psychologist Nick Chater, professor of behavioural science at Warwick Business School, and roving reporter Timandra Harkness.

Special guests this week include Sir Christopher Meyer, former British ambassador to the USA; Prof Nigel Harvey, psychologist at University College London; Dr Stephan Dombrowski, psychologist at the University of Stirling; Professor Daniel Oppenheimer, psychologist at the UCLA Anderson School of Management; plus Daily Telegraph columnist Sally Peck.