How cognitive biases important for us?

My media class and i read an article about cognitive biases last week. If you interested, you can check it out by this link: http://io9.com/5974468/the-most-common-cognitive-biases-that-prevent-you-from-being-rational

There are three biases that i spend more time to focus on: confirmation bias, ingroup bias and gambler's fallacy. In my opinion i think confirmation bias and ingroup bias are quiet similar. Those two biases talked about how people have a narrow-minded and confident about their perspective. However, gambler fallacy was different to thoes discrimination. It seem to more focus on a group of people as gamblers and it gave us a real statement and ideas to be thinking about. Therefore, i'd like to pick up gambler fallacy as an special topic to concentrate on.

It's called a fallacy, but it's more a glitch in our thinking. We tend to put a tremendous amount of weight on previous events, believing that they'll somehow influence future outcomes. The classic example is coin-tossing. After flipping heads, say, five consecutive times, our inclination is to predict an increase in likelihood that the next coin toss will be tails — that the odds must certainly be in the favor of heads. But in reality, the odds are still 50/50. As statisticians say, the outcomes in different tosses are statistically independent and the probability of any outcome is still 50%. Relatedly, there's also the positive expectation bias — which often fuels gambling addictions. It's the sense that our luck has to eventually change and that good fortune is on the way. It also contribues to the "hot hand" misconception. Similarly, it's the same feeling we get when we start a new relationship that leads us to believe it will be better than the last one. 

For me, i don't have any experience about gambler fallacy. However, in my own opinion think this bias often occur when people play gambling. The gambler have strongly believe in their sense. They usually feel like they come with their good luck. They think good luck will bring them money. However, it totally a wrong believe. It is not about luck or sense that they believe. The chance they win is 50/50 due to the risk taking is independent.

In short, cognitive biases are great. These ideas help us systematize our mind. Sometimes we have no ideas about why we can make a decision easily or even judge another people automatically. These is because of thier look, their personality, their behavior or because our biases was working. That is still the knowlege that we haven't understand profoundly and it is an interesting issue to learn.