Every succesful occasion of taking control and making a mark on the environment must strengthen the sense of agency. Computers offer rich opportunities of this sort. Along with a sense of agency - "I did that" - a sense of personal achievement and self-esteem may also emerge. When Ferenc replayed for the first time the 144 frame movie with its white line, he grinned with delight at the moment of resolution when the white lines join (and so did I!). Much less ambitious projects may bring similar rewards to less ambitious people. For example, someone with very few skills indeed can manage to run a Powerpoint show: just by leaving a hand on the space bar a whole series of favourite images can repeatedly cycle. That can be a thrilling achievement for some.

As well as boosting self-esteem, performance at the computer tends also to be genuinely valued by family and peers (sometimes by teachers too). This is of great importance for communicating with people with such acute insincerity detectors.