As a designer, your general knowledge of the world is as important as your general knowledge of the design practices. In order to understand how users make decisions, one should consider the various approaches to making decisions in architecture, politics, economics and social structures. This list of open-source tools can help you on your journey of interdisciplinary learning.
Architecture and Art
Theory of City Form, MIT
Aesthetics and Philosophy of Art, Oxford University
Culture and Philosophy
Foundations of American Cyberculture, University of California, Berkeley
Introduction to Visual Thinking, University of California, Berkeley
Ancient and Medieval Philosophy, University of Norte Dame
Ancient Wisdom and Modern Love, University of Norte Dame
Everything I Know by Buckminster Fuller
Economics
Inside Statistics, Harvard
Behavioral Finance, University of Western Sydney
Case Studies in Economic Development, UC Berkeley
Crisis, Globalization and Economics, Harvard
Economic Micro-Analysis, UC Berkeley
Economics Geography of the Industrial World, UC Berkeley
Finance Theory, MIT
Game Theory, Yale
Lectures on Human Capital, University of Chicago
Principles of Macroeconomics, Missouri State University
Psychology and Anthropology
Psychology and Economics, UC Berkeley
Philosophy in Film, MIT
Darwin and Design, MIT
The Art of Living, Stanford
Game Design, MIT
The Invention of the Modern World, Cambridge University
Introduction to Cultural and Social Anthropology, Arizona State University
Growing Up in the Universe, Oxford
Health and Culture, Arizona State University