Answer:

In 1990, when I released Mastering Elliott Wave (MEW), that was also my assumption. The statements in MEW were derived from 7 years of personal experience trading, forecasting markets and teaching Wave analysis. At the time of MEW's release, I had only witnessed one bull market and the start of one bear market; so, my market experience was limited. During the 25 years following its release, I've discovered neutral Triangles, 3rd-extension Terminals, Diametrics and Symmetrical patterns. All those new Wave phenomenon are explained in the Education section of the new NEoWave website - https://www.neowave.com/product-book.asp).

What I've come to realize, over 32 years, is that legs of a Triangle (if enough complexity is present) tend to mimic the behavior of the Triangle itself. So, if a Triangle is contracting, its last leg frequently contracts. If a neutral Triangle is forming, the c-wave or the e-wave has a strong tendency to produce a neutral Triangle. If an expanding Triangle is forming, wave-e has a propensity to form an expanding Triangle.

As an important end note, if your chart contains so much complexity that you can see a smaller Triangle form as wave-a of the larger Triangle, then your chart is TOO complex and must be simplified to avoid the subjectivity that comes with high structural complexity.