These techs' icons are pink in the upper-right corner, and are a system improvement that gives a flat bonus to approval (and possibly other effects on FIDS) once built. Technologies that increase approval in a system, in the Diplomacy/Trading tree on the left. The only hint I can give you is that most of these sorts of techs have an icon that includes a guy in a Buddha-like pose, except the first one. You can't just search for 'expansion disapproval' in the tech search box, either. (Applied Casimir Effect gives you the Colonization Program, Applied Atmospherics gives you Orbital Counseling, etc.) These techs have a green star in the upper-right corner, which is no help at all because almost all of the Exploration/Expansion techs have that green star. Each tech gives you -22% to the expansion disapproval. Technologies that reduce expansion disapproval, in the Exploration/Expansion tree at the bottom. There are three main ways to increase approval:
