Yes, social media can help SEO, but indirectly – just as other
forms of marketing can help drive more traffic to your website and
increase brand awareness and affinity (which generates search
demand).
While the impact of social shares (likes, tweets, +1’s, etc.) has
been denied time and again by Google through the years as
being ranking factor, it continued to be listed as having a strong
correlation in various ranking factor studies.
If you want to read more about this topic, I highly suggest reading
How Social Media Helps SEO [Final Answer].
20 YEARS OF SEO: A BRIEF HISTORY OF SEARCH ENGINE OPTIMIZATION