Why did large family size create difficulty for the Donner party? Disagreements between travelers became large conflicts as family members joined sides.
The many children in the group could not travel quickly.
Large families were difficult to feed and required many wagons.
Large families made the group look threatening to American Indians.

 Many other families' cattle and horses had also gone missing. The rigors of the journey resulted in irreparable damage to some of the wagons, but no human lives had been lost. Instead of the promised two-day journey over 40 miles (64 km), the journey across the 80 miles (130 km) of Great Salt Lake Desert had taken six. Led by brothers Jacob and George Donner, the group attempted to take a new and supposedly shorter route to California. They soon encountered rough terrain and numerous delays, and they eventually became trapped by heavy snowfall high in the Sierra Nevada Mountains The decision proved disastrous. The emigrants were forced to blaze much of the trail themselves by cutting down trees, and they nearly died of thirst during a five-day crossing of the salt desert. Rather than saving them time, Hasting's “shortcut” ended up adding nearly a month to the Donner Party's journey.

Explanation:

intimacy, passion and commitment are the components of a interpersonal relationship emphasized in the triangular theory of love by robert sternberg.

the triangular theory of love says love can be comprehend as this componest form the vertices of a triangle.  

intimacy relates to feelings such as of closeness and connection;

passion relates the drives that brings people together, as physical attraction.

commitment relates to the being in a long-term relationship.

it's