Why are daily scrums likely to reduce the time that is normally required for new team members to become productive

Daily scrums provide the opportunity for the team members to think, reflect on, and adjust the work done on a project.  This opportunity helps new team members to learn fast because of the interaction they share with experienced team members.  This means that the experience of other team members rob off on the new team members during timeboxed scrums, making them to become more productive.

Explanation:

Scrum is an agile project framework or approach that requires team members to meet regularly to solve emerging problems, reflect on their work through a process of iteration, and map out ways to accomplish tasks quickly.  Tasks are also prioritize based on the value that they contribution to the project development.