Social startups combine social missions with business goals, creating tensions they must manage. Incubators are expected to help, yet depend on funders whose funding shapes their programmes. This dissertation examines how expectations circulate through social entrepreneurship ecosystems in Tunisia and Morocco, and how incubators, positioned between funders and startups, shape the tensions arising from startups' hybridity. It draws on three qualitative studies using interviews, observations, and internal documents from traditional and social incubators. The first finds that incubation eases some tensions, creates others through its pace, and leaves external ones unresolved. The second distinguishes founders' explicit requests from their assumed needs, showing why both may go unmet and why some exceed what an incubator alone can provide. The third shows that funder expectations shape programme design, duration, and selection, reaching founders in ways they may not recognise. The originality of this thesis lies in following a single expectation across the funder–incubator–startup chain rather than assessing programmes in isolation, clarifying what support can and cannot resolve, and showing how incubators, funders, and policymakers can align expectations earlier.