Index: wp-content/themes/twentytwelve/style.css
===================================================================
--- wp-content/themes/twentytwelve/style.css	(revision 21428)
+++ wp-content/themes/twentytwelve/style.css	(working copy)
@@ -761,6 +761,7 @@
 	line-height: 1.846153846;
 }
 .entry-content p,
+.entry-summary p,
 .comment-content p {
 	margin: 0 0 24px;
 	margin: 0 0 1.714285714rem;
Index: wp-content/themes/twentytwelve/content.php
===================================================================
--- wp-content/themes/twentytwelve/content.php	(revision 21421)
+++ wp-content/themes/twentytwelve/content.php	(working copy)
@@ -30,10 +30,16 @@
 			<?php endif; // comments_open() ?>
 		</header><!-- .entry-header -->
 
+		<?php if ( is_search() ) : // Only display Excerpts for Search ?>
+		<div class="entry-summary">
+			<?php the_excerpt(); ?>
+		</div><!-- .entry-summary -->
+		<?php else : ?>
 		<div class="entry-content">
 			<?php the_content( __( 'Continue reading <span class="meta-nav">&rarr;</span>', 'twentytwelve' ) ); ?>
 			<?php wp_link_pages( array( 'before' => '<div class="page-links">' . __( 'Pages:', 'twentytwelve' ), 'after' => '</div>' ) ); ?>
 		</div><!-- .entry-content -->
+		<?php endif; ?>
 
 		<footer class="entry-meta">
 			<?php twentytwelve_entry_meta(); ?>