The best replacement for reaction time is age.

The best alternatives to reaction time are rated as following:
★★★★★  age
★★  response time
★★  reflex
★  reaction rate
★  choice reaction time
★  auditory reaction time
  visual reaction time
  hand dominance
  number of choices
  gender
  reflex time

Your alternative for reaction time is not listed? Suggest!
Speaking about reaction time, one probably shouldn't forget about dominant and non dominant hands.

Other search terms related to reaction time and their ratings are:
★★★★★ dominant and non dominant hands
You have in mind a companion for reaction time and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of reaction time in all years. Click on graph for more.
reaction time
age
response time