fei75766_ch07_206-241.indd 212  02/06/20 11:52 AM
Part II    Psychodynamic Theories212
Insimilar fashion, theegofollows thepathofepigenetic development, with
eachstage developing atitsproper time. Onestage emerges from andisbuiltupon a
previous stage, butitdoesnotreplace thatearlier stage. Thisepigenetic development 
isanalogous tothephysical development ofchildren, whocrawl before theywalk, 
walkbefore theyrun,andrunbefore theyjump. When children arestillcrawling, 
theyaredeveloping thepotential towalk, run,andjump; andaftertheyaremature 
enough tojump, theystillretain theirability torun,walk, andcrawl. Erikson (1968) 
described theepigenetic principle bysaying that“anything thatgrows hasaground 
plan, andthatoutofthisground plantheparts arise, eachparthaving itstimeofspe-
cialascendancy, untilallparts havearisen toform afunctioning whole” (p.92).More 
succinctly, “Epigenesis means thatonecharacteristic develops ontopofanother in
space andtime” (Evans, 1967, pp.21–22).
Theepigenetic principle isillustrated inFigure 7.1,which depicts thefirstthree 
Eriksonian stages. Thesequence ofstages (1,2,3)andthedevelopment oftheir
component parts (A,B,C)areshown intheheavily lined boxes along thediagonal. 
Figure 7.1shows thateachpartexists before itscritical time(atleastasbiological 
potential), emerges atitsproper time, andfinally, continues todevelop during subse -
quent stages. Forexample, component partBfirstemerges during Stage 1(infancy; 
Box1B),reaches fullascendence (bold line)during Stage 2(early childhood, Box
2B),andcontinues todevelop onintoStage 3(play age,Box3B).Similarly, allcom-
ponents ofStage 3existduring Stages 1and2,reach fulldevelopment during Stage 3,
andcontinue throughout alllaterstages (Erikson, 1982).
Children crawl before theywalk, walkbefore theyrun,andrunbefore theyjump. 
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