Antonyms for the phrase "more backslapping" can be described as reserved, critical or withholding. Reserved suggests someone who is shy, hesitant, or uncommunicative. Critical refers to someone who is analytical, discerning, or objective. Withholding describes someone who is reluctant to show emotion, uncommunicative, or secretive. These antonyms convey a sense of neutrality or even negativity, contrasting with the enthusiastic and congratulatory tone often implied by the phrase "more backslapping." Overall, there are many ways to express negativity or lack of enthusiasm, especially when situations call for objectivity or a critical eye.