Filters are both the best and the worst thing we humans have: Filters help us to function in the world without getting lost in the details. On the other hand, filters blind us in certain places. 

We need filters - but we should know them and adjust them regularly.

We are constantly bombarded with information. We don't have a chance to process them all. Each and every one of us has strong filters built in to understand anything at all.

But every filter also has a problem: it filters. It simplifies. Certain things are faded out. This leads to distortions of perception, to measurement errors or, in other words, to biases. There are dozens of biases. They can be categorised into three groups:

The information is endless, we have to filter out a part of it.

We only understand the world if we commit ourselves to one point of view. However, every perspective necessarily has a blind spot.

Without blind spots, there is no recognition.
There are infinite possibilities of how information is connected.

If we don't decide, there is no meaning. With every decision in favour of one context, we decide against other meanings.
Infinite information times infinite possibilities. It takes a lot of time to analyse all this.

Time that is often lacking, as this manager saying shows: Better a quick decision than none at all. Because those who do not decide, decide wrongly.
Strategy: Filter

We all filter mercilessly. That's not a bad thing. It's bad when you don't realise it. Here is a nice example of selective perception...
Strategy: Sensemaking

Our brain craves a good fit. What doesn't fit is made to fit. By omitting or adding information.

Strategy: shortcut to the conclusion

Under time pressure, we tend to rely on the familiar. A bird in the hand...

(Based on Bustor Benson)

Filters are essential for survival. We need them to function in our world. What is also needed, however, is systematic reflection on these filters. Which ones are no longer up to date? Where do I want or need to switch off a filter temporarily because it is masking important information? 

Buster Benson's presentation provides a good overview of known biases (click on the image to go to his website):

Further sources

A basic dilemma in leadership: The more clarity you provide as a manager, the greater the blind spots! Providing support and orientation

Many of the methods described aim to adjust its filters. In particular, give feedback. Effective feedback: fact and emotion

The constructivists explain biases from a different perspective (with different blind spots). For them, there is no reality and therefore no biases. Why reality is individual