block
class
classification
community
competition
concept
conflict
cube
difference
differential
economic
female
gap
group
high
income
inequality
low
lower
male
man
men
miniature
people
person
poor
poverty
power
pyramid
rank
relationship
rich
sitting
social
social stratification
stairs
stratification
stratum
structure
success
unequal
unfair
upper
wealth
woman
women
wood
wooden