People are often inspired and amazed at people's ability to overcome extremely difficult upbringings. Mariano Rivera, acknowledged to be the best relief pitcher in history, made a baseball glove out of cardboard and tape because his family could not afford a real one. Alice Coachman grew up with few resources and was denied access to training facilities because of her race; she ran barefoot and built her own high jump equipment before becoming the first Black athlete (and one of the first American track and field athletes) to win an Olympic Gold. Pelé, perhaps the most transformative figure in soccer, learned the game while using a rag-stuffed sock for a ball. These are some of the stories told in documentaries or biographies meant to inspire and share the challenges of unequal upbringings. Relative to the overall population, the number of people who rise from poverty to become very successful is small, and the number that become wealthy is even smaller. Systemic barriers like unequal education, discrimination, and lack of opportunity can slow or diminish one's ability to move up. Still, people who earn a college degree, get a job promotion, or marry someone with a good income may move up socially. Social mobility refers to the ability of individuals to change positions within a social stratification system. When people improve or diminish their economic status in a way that affects social class, they experience social mobility. Individuals can experience upward or downward social mobility for a variety of reasons. Upward mobility refers to an increase—or upward shift—when they move from a lower to a higher socioeconomical class. In contrast, individuals experience downward mobility when they move from higher socioeconomic class to a lower one. Some people move downward because of business setbacks, unemployment, or illness. Dropping out of school, losing a job, or getting a divorce may result in a loss of income or status and, therefore, downward social mobility. It is not uncommon for different generations of a family to belong to varying social classes. This is known as intergenerational mobility. For example, an upper-class executive may have parents who belonged to the middle class. In turn, those parents may have been raised in the lower class. Patterns of intergenerational mobility can reflect long-term societal changes. On the other hand, intragenerational mobility refers to changes in a person's social mobility over the course of their lifetime. For example, the wealth and prestige experienced by one person may be quite different from that of their siblings. Structural mobility happens when societal changes enable a whole group of people to move up or down the social class ladder. Structural mobility is attributable to changes in society as a whole. In the first half of the twentieth century, industrialization expanded the U.S. economy, raising the standard of living and leading to upward structural mobility for almost everyone. In the decade and a half of the twenty-first century, recessions and the outsourcing of jobs overseas have contributed to the withdrawal of Americans from the workforce (BLS 2021). Many people experienced economic setbacks, creating a wave of downward structural mobility. When analyzing the trends and movements in social mobility, sociologists consider all modes of mobility. Scholars recognize that mobility is not as common or easy to achieve as many people think.