A few extraordinary female singer-songwriters from the 1970s helped from music as we know it today, and continue to inspire so many with their soulful melodies (旋律).

Joni Mitchell

Joni Mitchells influence goes beyond her own generation. Her songwriting continues to be a source of inspiration for many, who regard her position as a pioneer of female expression in music.

The 1971 album Blue showed Joni's truthful self, telling the stories of her experiences in life and in love. Blue was later chosen by the New York Times as one of the 25 albums that represented "turning points and the highest points in 20th-century popular music".

Carole King

Carole King wrote or co-wrote over 118 hits between 1955 and 1999, making her the most successful female songwriter in the second half of the 20th century. However, King found herself less recognized than her husband and writing partner at the time, Gerry Goffin.

As the 1970s arrived, so did Carole King in full bloom. 1971 saw the release (发行) of her album Tapestry. The album was highly significant not only commercially but symbolically.

Joan Armatrading

Still in the 1970s but putting in the work on this side of the pond, Joan Armatrading became the first black British female artist to achieve international praise. Joan's place as a female pioneer in music continued as she became the first UK female artist to be nominated (提名) for a Grammy in the blues category, going on to receive two further nominations. An artist who is confident with who she is and what she wants to create, Armatrading famously keeps her private life to herself and lets her music do the talking.

A self-described "girly girl", nine-year-old Zandra Cunningham was constantly begging her parents for the latest beauty products. One day her dad simply told her "no", which inspired her to make her own.

Zandra has been recognized by Entrepreneur magazine as one of the youngest millionaires in America. When asked about her experience as a child entrepreneur（企业家）, Zandra says, "It wasn't frightening. When you're young, you don't have that fear mentality. ‘Maybe it's not going to work' never really crossed my mind." For Zandra, it became a challenge to separate her personal interest from what her customers actually wanted. "There were a lot of things that I felt were good ideas, but they wouldn't fit into the market," she says. Being part of the market herself, Zandra felt she had a unique perspective that allowed her to truly listen and respond to her customers.

It started as a hobby for Zandra and her mom. They'd play around with different ingredients until they found formulas they liked "through trial and error". Slowly, they started transforming the pastime into a brand. Zandra began selling her products at local markets, and a few years later—when Zandra was 12 years old—the family started a shop for Zandra Beauty. At the time, Zandra Beauty was one of the first brands to offer plant-based and organic beauty products at an affordable price. The 21-year-old has essentially grown up alongside her brand—but her goals have remained the same: "Our main focus is to push out amazing products that are safe for everyone and the earth."

"There're so many brands doing similar things, but there's still so much room to grow," says Zandra. "Your customers are out there, and you just have to find something that's going to set you apart."

Many people try to make society change for the better. The real challenge is how to get good solutions to scale up（按比例放大）for major change. New research suggests that social change may depend on the relationship between beneficial behaviors and policies.

The research, conducted by the University of Maine, University of Vermont and Université Laval in Quebec, Canada, attempted to understand how society can accomplish major, transformative social change, particularly the kind of social change necessary to solve the growing problem of climate change.

The researchers studied a behavior that benefits groups, but does not spread without policy support, such as a costly measure to relieve the effects of climate change. They created a mathematical model, which simulates（模拟）a society where agents live in groups and adopt the beneficial behavior of peers. That behavior, given the right conditions, can spread like viral, but not if the institutional costs are too high.

"Large-scale social change is not just policy or behavior, but the emergence of a new self-reinforcing（自我强化）system that combines both. This allows us to ask new questions, such as ‘how would a new pattern of behavior and policy spread?'" says Laurent Hébert-Dufresne, lead author of the study.

The results showed that both behavioral change and policy change are required to achieve large-scale social change—and that they need to happen together. Though neither can get the job done on its own, policy change is especially critical. They found that sometimes the beneficial behavior can spread too far. In some cases, the spread of behavior beyond groups with supporting policy can reduce its perceived success and slow the spread of the policy, thereby limiting beneficial social change overall.

In future research, the team aims to apply these types of models to all sorts of beneficial social change, particularly the challenge of tackling climate change.