I seem to recall reading somewhere that the force of the airbag deployment is adjusted depending on the weight of the driver or passenger. A light driver will be smaller and positioned closer to the steering wheel, so the system will reduce the force of the deployment. It probably saves the lives of countless Chinese women who are driving around in big BMWs or Mercedes. Ten years ago there were at least a couple a year in our city being killed by air bags because they were so short they had to literally move the driver's seat to within inches of the steering wheel to be able to reach the pedals. I haven't heard about it happening since they started using adaptive airbags.