How IKEA founder Ingvar Kamprad's bizarrely frugal habits and 'disagreeable' personality trait made him one of the richest self-made billionaires

Twitter/Ingvar Kamprad Swedish business magnate Ingvar Kamprad had been at the helm of IKEA, one of the world's largest furniture stores and most beloved brands, for more than 70 years when his death was announced Sunday. With a net worth of $48.1 billionat its height, he was one of the world's richest self-made billionaires. If you askMalcolm Gladwell, whose books have been read by millions of people, Kamprad succeeded thanks to an often-unpopular personality trait: disagreeableness, and not ca...