Our Gemara on Amud Aleph records a discussion between the sages Abaye, Rava, Rabbi Zeira, and Rabba bar Mattana about who would lead their learning group. As it became apparent that Abaye’s skill was superior, it was conceded that he should lead. The Gemara uses an interesting term: “Rabba saw that Abaye’s head was elevated,” to connote observing this superior quality.
A simple reading of the elevated head is a metaphor for being uplifted, perhaps having a superior vision above the crowd. Vayikra Rabba (26:9) states that if a short person becomes appointed to kingship, he gets taller. While this might also be seen as metaphorical, some take this literally. Pardes Yosef Hachadash (Chukas) offers testimony regarding numerous sages and tzaddikim who literally became taller when they were installed in their position. For example, the Tzemach Tzedek says that the day the Baal Hatanya became Rebbe, he grew a head taller. It is also said about R. Chaim of Tchernowitz that after emerging from the mikvah Erev Shabbos, he would appear entirely different, a head taller than before.
Fair or not, rational or not, it is a confirmed statistical reality that leaders tend to be above average in height. Researcher Nancy Blaker reports (“The height leadership advantage in men and women: Testing evolutionary psychology predictions about the perceptions of tall leaders,” Group Processes & Intergroup Relations, January 2013):
Research shows a positive relationship between tall stature and measures of status and leadership.
Height is positively associated with income (Judge & Cable, 2004), authority status in the workplace (Gawley, Perks, & Curtis, 2009), and military rank (Masur, Masur, & Keating, 1984).
Furthermore, individuals in managerial positions are taller, on average, than individuals in non-managerial positions (Egolf & Corder, 1991). U.S. presidential election outcomes are partially predicted by the height of the winning candidate—the taller candidate is twice as likely to become president (McCann, 2001).
What is the psychological mechanism? The obvious one is that taller people possess an intrinsic strength and physical advantage, which on an instinctive level inspires more aggression and assertiveness. Though intelligence and character are important in leadership, raw physical strength often trumps, and is certainly easier to quickly ascertain. Instincts take perceptual shortcuts, so while a cunning David could theoretically beat a lumbering Goliath, you can’t as easily detect intelligence at a glance, but height indicates strength and vigor. The data available for a split-second judgment favors betting on the tall leader, even though in time one might be able to ascertain the intelligence and wile of a shorter candidate.
Tying the statistical reality with this spiritual tradition, I will say: The more spiritual a person is, the more the line between metaphor and reality blurs, because everything is everything. We are all God’s construct and part of a divine plan, so the spiritual/emotional feeling of being taller and uplifted starts to manifest in the physical world. The greater the tzaddik, the more his spiritual reality dominates and becomes superimposed onto the physical. The opposite is true as well. Physical realities can spur the imposition of the spiritual onto the physical by mirroring. Thus physical cleanliness and spiritual purity overlap with practices such as washing hands before prayer (see Shulchan Aruch, Orach Chaim 7:2 as an example where physical cleanliness and spiritual purity overlap). Being tall might be a metaphor for spiritual elevation, but the physical and spiritual cross-influence each other, so leaders might actually be originally taller, and the spiritual masters become taller.