David T. Lykken's saying of "we could avoid two-thirds of all crime simply by putting all able-bodied young men in cryogenic sleep from the age of 12 through 28" demonstrates the understanding that with age.

testosterone level and aggressiveness decrease with age

Explanation:

David T. Lykken's saying of "we could avoid two-thirds of all crime simply by putting all able-bodied young men in cryogenic sleep from the age of 12 through 28" demonstrates the understanding that TESTOSTERONE LEVEL AND AGGRESSIVENESS DECREASE with age.

imperial crisis leads to civil war.

roman forces withdraw from britain as goths attack rome.

odoacer topples romulus augustus

huns attack the empire and drive german peoples ahead of them.

the density would be a smaller number.