@shawnspencer, IIRC, the W&M stat was arrived at by mistakenly counting individuals as couples, effectively doubling the percentage. If so, that would make W&M’s percentage similar to that of many LACs.
Many schools have a 60% or 50% intermarriage myth but the reality is usually closer to 10-15%.
At Colby, the myth is 50 percent and the reality 11 percent, while at Carleton it’s 60 and 15 percent, respectively. At Middlebury, the numbers are 60 and 13 percent. Bates is 60% and 12.5, slightly more if you count deceased spouses.
There are many ways to assess engagement. The “man on the street” reaction is one. My sense is that it depends a great deal on the size of the school and its sports prowess.
Another way to assess engagement is alumni giving. Alumni who feel close to their college tend to give to the annual fund. Percentages don’t differentiate by the amount of alumni gifts, so they shouldn’t depend (or at least not to a significant amount) on that amount alumni earn. According to USNWR the top 10 are,
Princeton University (NJ) 62.9% 1, National Universities
Thomas Aquinas College (CA) 58.3% 82 (tie), National Liberal Arts Colleges
Williams College (MA) 56.9% 1, National Liberal Arts Colleges
Florida College 54.4% 54 (tie), Regional Colleges (South)
Bowdoin College (ME) 54.2% 4 (tie), National Liberal Arts Colleges
Middlebury College (VT) 53% 4 (tie), National Liberal Arts Colleges
Davidson College (NC) 52.9% 9 (tie), National Liberal Arts Colleges
Wellesley College (MA) 51.4% 4 (tie), National Liberal Arts Colleges
Carleton College (MN) 50.6% 8, National Liberal Arts Colleges
Amherst College (MA) 49.2% 2, National Liberal Arts Colleges
http://www.usnews.com/education/best-colleges/the-short-list-college/articles/2015/10/20/10-universities-where-the-most-alumni-donate
Here’s a rating of the most powerful alumni networks. It only includes universities (so no LACs) and includes measures of job outcomes, not necessarily answering the family-like environment question, but it does give some information about alumni engagement.
http://www.bestcollegevalues.org/top-alumni-networks/