Re: How much shorter were people in the past than they are now?

Through hominid evolution, from australopitecines to modern humans,  there 
has been a general increase in body stature on average.  However, in the 
last hundred years or so there has been a secular trend in which we have 
seen each succeeding generation become larger.  This is a trend which has 
characterized Western populations.  It has been due to environmental 
factors such as changes in nutrition.  What is most important to note in 
reference to your question is that there is much variation between 
populations in the world as far as average stature is concerned.  I think 
that you have been dealing with Western populations in which the secular 
trend is relevant.  Many of the world's peoples have not gone through the 
changes that we have witnessed in the Western world.  Therefore there is 
disparity in population averages for height between different cultures.  
For your specific research I suggest that you search for the key concepts 
'human variation,' 'anthropometric measurements,' 'secular trend,' 'human 
stature,' and in regard to furniture and architecture check out  
'ergonomics.'