Progressing Through the Ages
Your score and your progress to the next technology level is determined by 1) How many Refugees live in your Village and 2) How happy they are! Every Bed gives you 1 Population, and each person has a Happiness from 0-2 based on how enjoyable their home is to live in.
Scoring Formula: Your score for every technology level is based on the formula: # Population x Average Happiness x Technology Level. So, if you have a single bed at Level 1 (Dirt houses) with a Happiness of 1.0, your Tech Level 1 Score = 1. If you have a single bed at Level 2 (Wood) with a Happiness of 1.0, your Tech Level 2 Score = 2. And so on and so forth.
Advancing to the Next Level: To unlock the next technology level your Village has to reach the Threshold Score for your current level. Generally speaking, reaching this score requires filling up ~50% of the Village Plot if your Villagers have a Happiness of 1.0. If you invest in more amenities to get the average Happiness up to 2.0, you can advance to the next level faster with a smaller Village because your Refugees will be happier and more motivated! For specific scores needed to advance to the next technology level, see Progressing Through the Ages.