The outcomes of many things are best modeled as a function of the product of all the inputs. Generally, the broader the scope of the activity and the more inputs involved, the more this holds true.
For example:
- A business needs good people, good marketing, good product-market fit, good leadership, etc. If any one of those is missing (or 0), the business will do poorly or fail.
- MMA fighters often lose fights because of their weakness in one particular area (striking, grappling, cardio, coaching, nerves, etc). Similarly, division champions are usually well-rounded and have developed all their skills to a high level.
- “All happy families are alike, but every unhappy family is unhappy in its own way” — Leo Tolstoy, Anna Karenina
- The most successful bands (however you want to define success) are made up of virtuosos. A bad drummer, a bad bass player, a bad guitar player can single-handedly ruin the band’s music.
There are two sayings that are relevant to multiplicative effects. The first is, “A chain is only as strong as its weakest link”. The second is, “The whole is greater than the sum of its parts.” For cases where multiplicative effects apply, there are many ways to lose and few (or one) way to win.
If we apply this idea to MBTi functions, we can model your overall effectiveness as the product of the development of your four functions. In other words:
Effectiveness = Savior * Parent * Child * Demon
We’ll assume your middle functions (parent and child) are relatively balanced in a 60–40 ratio. So your Parent function is developed 6/10 and your child function is developed 4/10.
For most people, their Savior function is way stronger than their Demon function, so we’ll say the ratio is 90–10, which means that the savior function is 9/10 and the demon function is 1/10 in terms of development.
Bringing this all together, we get:
Effectiveness = 9 * 6 * 4 * 1 = 216
At this point, if you have the choice to spend time and energy to develop any of your four functions, the most effective use of your resources would be to develop your demon function. See below:
Developing Demon: Effectiveness = 9 * 6 * 4 * (1+1) = 532 (!!)
Developing Child: Effectiveness = 9 * 6 * (4+1) * 1 = 270
Developing Parent: Effectiveness = 9 * (6+1) * 4 * 1 = 252
Developing Savior: Effectiveness = (9+1) * 6 * 4 * 1 = 240
Thus the importance (and effectiveness) of developing your last function. In practice, this is done most effectively via your second (or Parent) function.
