An optimum level of arousal or stress is needed to fire up the neurons in the prefrontal cortex of brain to result in high performance.

Instilling fear and increasing stress levels results in the flow of chemical noradrenaline to hike performance.

A much better way involves using humour and conmunication of positive outcomes.This results in flow of dopamine as well thus being a much more effective way to increase mental performance.

This is the reason why mentoring is a much more effective technique compared to Carrots & Sticks to hike performance.