What causes static electricity in everyday life?

Static electricity is caused by the transfer of electrons between materials when they come into contact and then separate. Some materials hold onto electrons tightly while others give them up easily, so when they rub together or touch, electrons move from one surface to the other, leaving one object positively charged and the other negatively charged. Common everyday examples include walking across carpet and touching a doorknob, where electrons transfer between your shoes and the carpet fibers. Pulling clothes from a dryer causes static because different fabrics exchange electrons as they tumble together. Dry air makes static more noticeable because moisture normally allows charges to dissipate gradually, which is why static is more common in winter or low-humidity environments.