When making decisions about far-reaching policies, reports and consultation responses concerning that decision could be interpreted based on the bias of a pre-formed choice.

Evidence is then understood in a certain way depending on its support for that decision. With HS2, once the Government were fairly sure they wished to commence with this project, all reports would be considered in relation to this. Those that provided evidence to support the route would be promoted, whereas those that suggested alternatives would be discounted or buried.

This is a natural instinct; to rationalise our decisions and convince ourselves that we have made the best decision.

In truth, most decisions could be spun to appear as the correct choice. Facts can be interpreted in a myriad of different ways and new information will no longer be received as neutral once a path has been chosen.

When we look for evidence to support this path, we will find it, by perceiving what we wish to perceive.

This can even happen without our conscious knowledge of it, and so Governments can believe they have considered all evidence fairly when in fact they are operating under bias.