mrspoonsi writes "Studies suggest red-haired women tend to choose the best passwords and men with bushy beards or unkempt hair, the worst. These studies also reveal that when it comes to passwords, women prefer length and men diversity. On the internet, the most popular colour is blue, at least when it comes to passwords. If you are wondering why, it is largely because so many popular websites and services (Facebook, Twitter and Google to name but three) use the colour in their logo. That has a subtle impact on the choices people make when signing up and picking a word or phrase to form a supposedly super-secret password. The number one conclusion from looking at that data — people are lousy at picking good passwords. 'You have to remember we are all human and we all make mistakes,' says Mr Thorsheim. In this sense, he says, a good password would be a phrase or combination of characters that has little or no connection to the person picking it. All too often, Mr Thorsheim adds, people use words or numbers intimately linked to them. They use birthdays, wedding days, the names of siblings or children or pets. They use their house number, street name or pick on a favourite pop star. This bias is most noticeable when it comes to the numbers people pick when told to choose a four digit pin. Analysis of their choices suggests that people drift towards a small subset of the 10,000 available. In some cases, up to 80% of choices come from just 100 different numbers."