It's Stephen Hawking's 70th birthday this week and the University of Cambridge is celebrating with a conference in his honour. If it's going to be as exciting as his 60th birthday, and it definitely looks like it will, then we're in for a treat! We'll be giving you articles and podcasts from the conference soon, but in the meantime, here's what we did for his 60th.

Human reasoning is biased and illogical. At least that's what a huge body of psychological research seems to show. But now a psychological scientist from the University of Toulouse in France has come up with a new theory: that logical and probabilistic thinking is an intuitive part of decision making, only its conclusions often lose out to heuristic considerations.

This is it! Merry Christmas to all you beautiful Plus readers and listeners from the Plus team! We hope you'll have a marvellously happy 2012! And since Christmas is all about getting together with the folks, here's some family maths. You might not be able to choose them, but at least you can analyse them!

Christmas is a time of mysteries so we thought we'll give you the chance to put your favourite mystery to the experts. Pick a question in the poll on the right — after Christmas we'll answer the most popular question in articles and podcasts based on interviews with physicists and mathematicians who really know about these things.

Oh! Look! The Higgs! If only we'd known it has been hiding behind this door all along.

Apart from the Olympic Games and Alan Turing's centenary, 2012 will see another important event: the 15th birthday of Plus! To get into party mood, here are the 5 most popular Plus articles since current records began. A big thank you to the wonderful and generous people who have contributed these and all other Plus articles!

It's dark and grey this time of year, that's why we cheer ourselves up with lovely sparkly tinsel and colourful baubles. But if that isn't enough for you, here's another chance to bask in some glorious colour.

Everybody needs a little love on a cold, wet Monday morning, so here's some for you with lots of kisses from the Plus team!