When we design anything, be it user experiences, gamified experiences or even just Lego buildings – we become emotionally involved with what we are doing. We invest ourselves in the process and the outcomes of the process.
Because of this, it can be very hard for us to accept someone telling us that they think we may be wrong. When they tell us you should really have used a 4 block not a 6 block on that side of the wall to make it stronger, but we have already finished the wall – the last thing we want to accept is that they may be right and taking apart the wall would lead to a better end model! So we engage our Confirmation Bias to help us justify continuing on what may well be the wrong path.